Alot of drummers have trouble when they get older, I think moreso than other rock instruments. That said, Edge was pretty obviously the least talented member. He barely wrote any real songs.
When you say you had their '70s albums do you really just mean the '70s and not the 60s? Days of Future Passed and To Our Children's Children's Children are their best albums and those are from the '60s. That said, A Question of Balance and especially The Seventh Sojourn are very strong, and even if you don't like them I have trouble seeing them, or the other two albums, as "bloated."