Best mode for 7.1 on the 950?

I'm trying to buy time until I get the new Outlaw preamp with my 7.1 system.

I just installed the rear 2 channels. What is the best surround mode in the 950 for 7.1? Should I select Dolby Digital EX for everything (except maybe music)?

Thanks!

I'd use Cirrus Extra Surround - it isn't prone to collapsing the rear channels like EX is, plus you can use it with Pro Logic II.