One big advantage for Sansa is the memory slot. I also use the radio a lot which isn’t exclusive, but narrows the field if I was switching.
I’m using Rockbox on an e270, so most firmware features people have asked for here have already been addressed 
If you decide to “stray from the flock” I’d suggest checking out the user forum for whatever brand you’re considering. If there isn’t one on the MFR site, there are a lot on Yahoo.
