Hi
There are two versions of e200 (V1 and V2).
Rockbox in v1 is very stable.
the rockbox V2 firmware was released at the same time as the fuze firmware and are relatively new, so I am not sure how good the rockbox implementation is. It should be OK. In fact, I am running rockbox in my sansa Clip v1, which is even newer and it is excellent. No crashes or hangups whatsoever. I assume that it is the same with the e200V2 and fuze, but I need to find the time to install the firmware in my fuze to see.
In terms of sound quality, from best to worst, here is the line up 1) fuze 2) e200V2 3) e200V1
The e200V1 has very poor sound quality. Whenever the player is accessing memory, there is static/hissing or digital noise coupled through the headphone output. I have had to use an inline headphone attenuator and crank the volume up so that I won't hear this noise as much. It also seems that rockbox makes this noise even worse.