How is the size of the mamba compared to the dx50 ??
Well as for rockbox, i kept switching back and forth too many times and felt confused, at the end i felt that i tend to like the warmth of the stock firmware, but everybody else seemed to like the neutrality of rockbox and even said it had more details, so due to these opinions , also due to my confusion and finding it hard to settle which is better + rockbox features from playlist to equalizer and crossfeed.
I ended up with rockbox without looking back, and its great for me.
You have to try it anyway..
Same here looking forward to next stock firmware !!