Heh I am already settled with mine so it doesn't matter to me since my choice is made but others may want to bug Brittany xD (just joking of course).
Well, I think the effectiveness of an amp will have a lot to do with what is plugged into the input and output. An iPod playing lossy files? Pre-degraded sound quality. An IEM (as opposed to a full-sized headphone)? A lot easier to drive. Combine the two, and you have a recipe for thinking that amps aren't worth the cost.
Anyway, that silly business aside, I am surprised your M3 has so much hiss, is the gain set rather high?