My kids have been hiking a bit with me this summer, and we've run across a few parties doing the 92 mile Wonderland Trail in 3 days. These people have been wearing basically a CamelBak and carrying a water bottle, made possible by the fact that each night they are supported by meeting a relative or buddy who sets up camp, feeds them, and resupplies them for the next day, where they will be met again and repeat the process to finish on the third day. This is an ideal way to "flash" the trail with the minimum amount of equipment, offering freedom to lope along at a fast pace to cover the 30 or so miles required per day. Now, I won't call this cheating, but I can't consider this a backpacking or fastpacking trip, as the "packing" is missing from the formula. I think of this regime as supported day-hiking. This is certainly one way of covering the distance quickly.
One might read a "but" in that last sentence and it is only a philisophical view. It's a worthy feat to cover this terrain in 3 days but bottom line, if you don't carry everything you need for your entire trip with you, then you didn't really do it on your own. Let's compare two Ultra races, the Western States 100 and the Plain 100. Western States is the "Boston Marathon" of ultras, indeed employing over 1400 volunteers to help out. You cruise into an aid station (about every 7-10 miles) and someone takes your water bottle and asks "do you want ice in that"? Food is layed out in abundance, there are people to help you treat your feet, you are monitored for too much fluid loss for safety, there are light sticks to help you find your way at night, there is even a person in a wetsuit to help you at one of the major river crossings, just in case that line strung across there isn't enough. And then there is the Plain, where no aid is allowed, even from another runner, you have to find your own way, you have to carry everything you'll need with only one chance to resupply yourself about half way through. I've done both races (not finishing the Plain) and consider the unaided version much more of a test of mettle.
So from my purist point of view, I can see the allure of trotting along the Wonderland by day, meeting someone at night that provides me with shelter, food, fluid, resupplies, and moral support; but I just can't help myself, if I'm going to do the distance, then I gotta take everything I need with me, or somehow (for me) it just doesn't count. And yes, I have done the trail in 3 days, and once in 36 hours, and I took everything I needed with me....on my own, and just the way this purist likes it.