Welcome to MVP!
As I've stated before, I seem to be the outlier with my upgrade luck. Of over 50 segments this year I've only had luck on 4. So, it varies. Despite that, always "request" the upgrade - you never know.
MVP is much more than upgrades to me (because I never get them!). Boarding before the masses of people is huge in the day of fee-for-baggage. As was mentioned, the ability to book "premium" coach seats is a plus.
I also enjoy my benefits over at DL. I don't board with sky priority, but I do board with silver medallions, which is again HUGE considering the masses. As MVP you are also entitled to book premium seats with DL.
Obviously this is all stated on the MVP/G bennies page, but I wanted to stress that even if you virtually never get an upgrade, there are plenty of things that make travel much more pleasant.