Yes, it's horribly unscientific. But I've found in life that frequently if complex testing and calculation is necessary to decide if something is (that much) better ... The answer is generally no.
For thumb drives I look for something from a trustworthy brand with a deep cap (for protection), that is big enough (to do what I want), and cheap enough (to not break me). I once purchased a Corsair TD with a rubber case that was supposed to be "water resistant" because I was starting to take the bike to work more and rain of course is always a factor in Florida.
The problem was that the shallow cap only just covered the plug on the end. So when I shoved it into the watch pocket of my jeans for quick access, the first time I sat down it cleanly snapped the plug off of the internal board...rendering the drive quite useless. My old at the time PNY TD had a deep cap that slid down over the drive about half way. With it in the same watch pocket it would just stab me in the leg when it slipped out of position...instead of snapping in half. I still have the broken Corsair drive on my desk at home to remind myself why that was a stupid idea.
The Lexar has an excellent cap that also allows it to handle getting wet rather well. The data I keep on it is relatively static, but I do occasionally either back it up (which never takes long), or use it to quickly sneaker net an ISO or other large file to/from the office. As life would have it I frequently end up doing these types of things at the last minute, and so am in a bit of a hurry at the time. This is my version of a real world performance test. Will it take a 3GB ISO fast enough for me to get out the door in the next 10-15 minutes..?
Yes = Good Device
No = Keep it under 20min and I probably won't smash you with a hammer.
Hell No/30Min+ = Somebody (most likely the device). Is. Going. To. Die!