Lexicon MC 1 change to MC 4 ?

I have a Lexicon MC1 version 4. I was thinking of moving to the newer MC4, I heard great things about it but cant get them in the same room unless I buy an MC4.
I would appreciate comments from anyone who has heard them side by side or knows both well enough to say which one is better for surround audio. I am not concerned about video switching as I dont use that portion at all.
Thanks for your help !!
I made the switch from MC 1V4 to MC4. The MC 4 is a little brighter than the MC1. The MC4 is more resolving than the MC1.
I am glad I made the switch.