I’m leaving this review as it was written in 2014. Please note the edit at the end of the article (January, 2019)
Well, I've used the Zpacks Duplex for a year now with enough time to render some observations. To qualify, I am not talking many nights, as I use a number of different shelter systems depending on the trip. Probably the best test was this year's Pasayten Wilderness hike with my daughter where we spent 8 nights out. That said, my general impressions are this may be as close to the ideal backpacking tent as a manufacturer can come. The reasons?
• Situp Room: I've owned tents from Mountain Hardware, Gossamer Gear, Garuda, and Tarptent. Naturally there are pros and cons for every example, and in truth this is also true for the Duplex. But this tent provides just the right amount of peak height for two adult males to sit up and attend to things like changing clothes or whatever, a vast improvement over tent designs that have a single entry and peak towards the front.
• Dual Entries: Two half moon zippers provide each occupant with their own access, plus vestibule. My daughter and I found that we would use one side for entry/exit and the other side to stash our packs under cover. We just had to coordinate night time nature calls.
• Taut Pitch: We never experienced what could be considered high winds, but once the pitch was made the non stretchable cuben maintained a nice taut line. The design of the tent seems to have enough geometry over the two poles to deflect winds from every direction, especially with both vestibules down. We used 8 stakes in the pitch. In general I find the ultralite titanium stakes adequate; however, the hi viz coating comes off in a hurry when trying to pound into firmer ground and the stakes can easily bend in more difficult securing conditions. I much prefer the titanium V shaped for robustness and poundability, and ended up using a combination of 4 and 4. ZPacks offers different stakes with these considerations, mine are from Gossamer Gear. Notice in the photos that the tent also has four additional tie out points for further stability. The supplied stuff sack is sized correctly, where I could roll up the tent and stuff it away without problems. This may seem a minor point but consider packing up on a cold and wet morning, conditions where I find my fingers going numb from handling wet material. The four letter words that emanated from my mouth trying to tuck away my Tarptent or GG Squall in these conditions were absent this year. Finally, the packed tent is small enough to place inside your pack without taking up much real estate, depending on your style.
• Cordage: The tent comes with supplied cordage which must be cut to length (specified) for the tie outs. With the exception of the two main tie outs for the doors, the rest of the guy lines are fixed length with loops. This is a perfectly acceptable configuration, just be aware that you must position the stakes in exactly the right spot to get the taut pitch. If you want more flexibility, you can use guy line adjusters to adapt the cord to where the stake might be better positioned, dependent on the soil. If you have tripped over guy lines at night like I have then you will appreciate that these have a reflective coating.
• Quirk 1: This tent does not like to be pitched on an incline (or any kind of uneven ground). One night we had to pitch in a meadow with no level areas. We found the bathtub floor always migrating downhill and this in turn pulls on the netting with the uphill zipper to where you could not close it back up (if used). The only way was to somehow unweight the floor so it could be slid back into position, something not easily accomplished with two people and sleeping gear taking up most of the available area. In this circumstance, the tension on the zipper, netting material and fasten points to the main tent was cause for concern, although we experienced no failures. Of note, I did use a polycro groundsheet. Pitching directly on the grass may have resulted in less slippage.
• Quirk 2: The tent does not like to be pitched at any level above or below the suggested 48 inches. Once I had it pitched too high and just couldn't get the fabric to smooth out, orbiting the tent redoing stakes to no avail. Another time I tried to purposefully pitch the tent lower in anticipation of wind blown rain with the same results, eventually giving up and going back to the 48 inches. As it turns out the tent was fine in the blowing weather at normal pitch with no intrusion of rain inside.
• Poles: I ended up purchasing the carbon poles for the tent. They are extremely light weight, the exact right size and they free up my trekking poles for other use (base camp day hike, camera mount etc).
• Condensation: A concern with any shelter, especially a single wall. If I had to rate this tent based on my experience, I'd give it a 7.5 out of 10. This means that in the morning there was some moisture near the head and foot of the walls, noticeable if you brushed against it, all dependent on the amount of airflow during the night, whether the vestibules were open or closed, and the conditions of the campsite. I have yet to use a single wall tent where there was zero condensation. What makes this tent better than my others is the amount of clearance. With two adult males (6') or myself and my daughter, we could easily avoid contact with the tent interior walls at each end or when sitting up. I found that using a pack towel to wipe both the interior and exterior before packing up kept the tent clean and dry for each night.
• Price: You pay for it, not cheap at $595 (disclaimer, I purchased mine from Zpacks at a discount). However, the size is right and so is the weight: 20 ozs/567 grams. I don't own a scale and go by manufacturer's weights. Adding the poles (4 ozs/113 grams) and stakes (2 ozs/57 grams) brings my total weight to 26 ozs/737 grams. This weight is low enough that I would consider using this tent as a solo shelter (longer trip, isolated, varying weather conditions, etc). I find the material robust; exercise normal cautions (watch the crampons, don't throw knives, sit with pokey pens, etc) and this shelter should last many years. Another consideration: cuben is easily patched with cuben tape or duck (or duct) tape.
• Service: Simply put, Zpacks is renowned for customer service. My personal experience can attest to this, with Joe answering emails in a timely fashion, repairing a pack, and accommodation of tight schedules. I needed a new Challenger Jacket in the longer size for a particular trip where I used it in conjunction with a custom 3/4 bivy (also Zpacks made) as a shelter system. Despite advertising multi week waits, I had the jacket in hand two days before my requested date. When making a major purchase like this, remember to consider the whole package....it's not just about the product you are buying, but the company and people behind it. Zpacks scores on both accounts.
• Summary: In case the reader is on a tight schedule, here's my bit. Considering the pros, cons and observations listed above, I consider this close to, if not THE ideal backpacking tent (mountaineering is a whole different ball game) currently available, especially for duo hiking.
EDIT (Jan 2019): My Duplex was just after the prototype phase and has evolved over time. The Duplex now comes with adjustable line locs on the tie outs so no need to orbit resetting stakes as I describe above. The fastening hooks for the vestibules have been improved and the tent now comes with a standard pocket inside for asundries. I’m sure there have been other improvements in the design over these past 6 years. I’ve had the tent out in some blustery winds (the kind that keep you up at night) and the tent held up well with no problems. The Duplex can be drafty with wind so definitely take this into consideration; great for alleviating condensation issues but not great for blowing sand or dust. This is still my go to shelter when a tent is called for with two people, and I still consider it a fantastic shelter for two for general backpacking. However, if I’m going into exposed conditions with high winds and/or snow loads, I’m still taking a mountaineering tent. However, this tent still is a top contender for utility, weight and packability. Plus, there are many reviews and observations out there (after six more years) that the reader can avail themselves of in making a decision on a tent purchase. I’m still really happy with this older Duplex!