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

OK, 
So I have read all your replies and I am even more confused :-)
What exactly is BTS for??  Is it for demo purposes?
There doesn't really seem to be any correlation between patterns and 
BTS.  BTS will continue playing even after the pattern is stopped.  
Triggers do not bring BTS parts in on the beat (e.g not in sync with 
the pattern), unless you hit Audition to bring the BTS in.  Also you 
cannot record the BTS parts in pattern or song mode.  
Are all these assumptions correct?  Also how do you make your own BTS 
presets (as some of you seem to be doing.)  
The BTS riffs do sound very cool (I spent over an hour jamming with 
Rocket ... I think that's what it is called), but either I am not 
using them correctly or they are not very well integrated into the XL 
interface.
Does the XL1 Xtreme Lead behave the same?  Maybe the XL-1 manual will 
shed some light ... I'm off to find it now.
Thanks,
Justin.