question about sansa E220V2

[NickInUse]

i just noticed that rockbox now support e220v2 but its unstable.
according to this page:
http://www.rockbox.org/wiki/SansaAMS
the only problem with V2 is USB. what does it mean? that if ill install rockbox i wont be able to charge my sansa? or adding songs to it? if so, is there a way to switch between the original firmware and rockbox, so i be able to load it?
and how the whole things with the games and themes works? how will i know what will run on my sansa?
thanks!!!

[mc2739]

Rockbox for the e200v2 and Fuze does not currently support recording and USB.  This means that both of these functions will require you to boot the original firmware for their use.  Charging will work in Rockbox by holding the select button when you insert the USB cable, or it will charge while transferring files during a USB connection.  When you insert the USB cable without pressing the select button, it will reboot into the original firmware for file transfers.

Games and themes do work, except that Doom will currently have a problem at the start of the second level due to limited memory.

[NickInUse]

thanks! now i finally have rockbox D: