Emu XL-7 & MP-7 User's Group

Quick reply to add a few things; it seems others have supplied most of the answers.

(1) Yes, you can put ROMs in a P2K or an XL-1 (or any of the others), but the big difference is 16 controllers versus 12 controllers. (I know I have written about this extensively; perhaps search 12-controller and 16-controller (unless Yahoo search ignores the hyphen). 

Any patches that use MidiM->MidiP in patchcords will not have those controls. I believe the patch will show up with ???? where you edit the patchcords with unavailable resources.

(2) I may have tested the Knob Hold button once or twice, but I never use it.

If you get a portable, one rack unit module, I'd recommend one that has 32 midi channels--particularly if you want to do stuff with the arpeggiators. 

Steve