I learned that lesson when I nearly bricked my Lumis Host trying to update that firmware . I can't wait for my 4520 to get here next week ( you guys keep buying them out from under me - hard to keep in stock ).
I'm going to install it and wide speakers and go straight to 9.1 with my new Martin Logan speakers.
Then phase 2 will entail an amp, height speakers and perhaps a 2nd sub. Why the heck not, eh?