I didn't even think about the different e series there were. I've got the e270 version 1 so I was able to Rockbox it. I also have an e260v2 but don't use it much because of the lack of RB. My 260 actually now has 14GB of storage because RB enabled me to use SDHC cards in it so I got an extra 8GB on top of the internal 6.
The Q was my primary source for everything mobile but the 2gb storage limit and Windows Mobile 5 being pushed to what seems to be its limit made me buy the Sansa. VERY glad I did.
Plus, RBs user interface with the sansa scroll wheel is light years ahead of the windows media interface in windows mobile. Especially while driving.
I feel really bad for one guy. He posted on the Zune forums that when his got stuck on the boot screen he was so peeved that he threw it out the car window. He says he dropped his onto a concrete floor last night, and when it wouldn't boot this morning he thought that he had broken it the night before.
Here's an update on mine: As I'm typing this post (8:45 Eastern time) my Zune has been plugged into my computer charging. I just noticed that it syncronized, and I was able to start a song playing. Its fixed (for now), but I hope M$ gets the firmware resolved sometime soon so this doesn't happen again in 4 years.
Lucky I have the 8gig Zune that I have not turned on for a few days, and Sansa, iPod, V-Touch and a few other various media players including iPaq that had it all 5+ years ago. Other than the problems of trying to turn off the ZUNE it is a very cool product - too many button presses to make it do things however. Typical Microsoft menu happy programmers.