Unless you're getting a screaming deal, I can't really see the 8.8 Ford being a big improvement. Full floating is nice if you really think regularly breaking axles are a probability. The 8.75 mopar is a semi floating design so if you DO break an axle, they are not going to come apart like a C clip axle would be. And, with aftermarket axles, 8.75 can be very, very tough.

Additionally, the 8.8 Ford lacks the easy and inexpensive gear changes of the Ford 9", so you don't gain anything there.

I think they beef up the 8.8 because of their popularity with/and/or rule requirements in Mustang racing classes.