Rockbox: so many functions, so few buttons...
That is a neat feature, very handy for long podcasts or whatever. But Rockbox has a bookmarking functionality, and a fwd/rvs scanner that is accessed by holding >>| or |<< .
(press on menu, long press on menu, press on select, and long press on select are all used for quick access to several functions already).
Hope this helps. Remember, you can keep the original apple firmware and rockbox and switch between them so you can easily try all this stuff.