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

Hi everyone. A friend of mine wants to trade his 505 for my XL-7 (plus cash). I have a couple of questions.

 I'm assuming that some of you are 505 expatriates. Has anyone used both units with SonarXL? Any advantages? Does one unit work better with Sonar than the other?  Alos, I'm running a Boss dr-202. Will it 'fit' better with the Roland or does it even make a difference? 
 I know the 505 has hardware limitations (no expansion, shitty presets, etc). As stand-alone, does anyone have opinions about the machines vs. each other? I do like the sexy part-mixer on the 505, but I also like my 16 tracks on the XL, not mention the USB. 

 Thanks in advance, Brian