I have switched from Cowons to iMods. The Wolfson DAC is pretty great, so 5.5 Gen 80 GB iPods (used off eBay) converted to iMods by RWA (or someone, I prefer Vinnie ... Craig at Whiplash is another possible choice) really hit all the right notes: tons of storage, best interface, fantastic SQ with the right LOD, excellent battery life, a little large by today's standards but still easy to pocket lashed to your favorite small amp (Predator? Shadow? Pico? iQube? Mini^3?), what's not to love? (I have had all those but the Pico. Sold the Predator and still listen to the other 3, but only the iQube and Mini^3 have dedicated iMods, the Shadow is strictly for micro size, mated to a 2 Gen 8 GB Nano, not modded, regular LOD).
iMods are expensive but will last a long time, worth it IMO.
With 24/96 digital files down-converted carefully to 16/48 ALACs, RWA iMod+ALO LOD+iQube held together with the black band supplied by iQube, and Shure 530s ... OMG, I had SQ approaching my home 'stat rigs. I sold the 530's and will move to JH's I hope soon, after more reviews of their new amp with DSP come in.
I use a PC and FB2K and/or XPlay 3 to manage my iMods ... never touch iTunes. I use SOX in FB2K to make 16/48 FLACs from my 24/96 files (adding cover art via MuvUnder Cover), then the amazing Xrecode II to make the ALACs (which preserves album art, FB2K does not). I know others use MediaMonkey, dbPower Amp, etc. instead. To each his own!
Choice of IEM/phones trumps all this talk of the PMP SQ. And I agree with other posters: user interface, touch control sensitivity, battery life, form factor ... all should weigh heavily.