wow, didnt think that this would go stupid americans... but yea lets go with that.
id say most people have that placebo effect, and with any computer, unless you tell people flat out what to look for, it will be hard to identify anything as better or faster.
telling them its the iphone 5 and haveing them try to figure out whats new, well... yea... they will try to find out everything.
i also want to say that i dont know this, so any one can verify, does the iphone get slower the longer you have it? i mean with all the crap you put on it, will it make the thing noticeably slower? if it does i cant blame them for thinking its faster.