I snagged an E345 16GB a few months ago on an Amazon sale for $70 and I have been fairly impressed. Not that I use it this way regularly but it sounds decent driving HF-2's, not that they are high impedance but they are full-sized cans, and it sounds great with 'flat' settings driving various portable phones/IEMs (there seems to be good synergy with Brainwavz M1's) and of course having the EQ options adds flexibility. I chose it over the Clip+ because of the battery life and although it doesn't have 'infinite' storage because of no expansion 16GB is ok for select parts of my library @ 128kbps VBR for mp3s. I thnk after trying a few DAP brands (Cowon D2, MS Zune 120, original Clip) that Sony has won me over.
My next DAP however will have to be 64GB minimum, or maybe I will hold out until 128GB is reasonable, say <$200, although I would consider a 128GB 'MID' type device like if Apple put out a Touch with the $15/month 3G access that the iPad has around $400. I was expecting a lot more in terms of GB/$ for this season seeing as there is a flash process shrink happening from all flash makers but it looks like the CE device makers aren't really taking advantage this year. I would like to just dump my whole library at 256kpbs VBR onto a device with plenty of space to spare but a 64GB device won't even do that for me now.
The biggest change to the E series looks to be the battery life. 50 hours in such a small form factor is great.