Source is the most fickle part of an audio rig. There is never 1 source that is good in everything for sure. I know this coz I've had my fair share of DAPs. I can surmise the following:
iPods - they are OK sounding players. The iPod 5G is probably the best sounding one I've heard, plus you can use Rockbox on it. Still, I do find that I need to amp the iPods to get a decent sound.
clip+ - After having only iPods, the clip+ was a big surprise. Much better sound quality from a much smaller player. Unfortunately the poor battery life and small screen and size really killed it for me.
s:flo2 - Bad customer service aside, the s:flo2 sounded excellent. It deserves the praise it gets for its SQ for sure. However for me, SQ isn't everything, and eventually the really bad UI and awkward shape made it a bad package overall.
Fuze - Currently using and so far it's the best. Good battery, easy navigation, Rockbox. Don't underestimate the Rockbox impact. Coupled with the Fuze's amp, it pretty much nullifies the need to use an amp for me. I've tried iBasso D12, P4, D4, Cordas, everything short of RSAs, and find that there is very minimal gain using an amp. I think a lot of people can atest to this, judging by a good number of Fuze rigs here without amps.
So yeah, I don't feel the Sansas are overrated. They are definitely bang for buck, and then some more. Maybe Cowons or the s:flo2 may sound better, but they all have their own problems. After the nightmare that is mp4nation customer service, I'm inclined NOT to spend too much on a source anymore. :)