A lot of the MTV catalog at the very least is leaving me wanting. Just for instance, MTV Unplugged only has 8 random episodes (this has been a running series since 1989 that still to this day gets the hottest acts of today on to perform.) VH1 Storytellers - same deal. Also, absolutely no Road Rules seasons, seasons missing from The Real World, The first 10 seasons missing from The Challenge, MTV Cribs is missing a ton, etc, etc.
This isn't just limited to MTV though, there's missing episodes or seasons all over the service, which is a bit disappointing. I know Paramount basically had licensed a whole slew of their content away before they really committed to streaming, so that's probably why a lot is missing and I expect it'll get better over time, but right now it leaves some to be desired.
However, I signed up for certain reasons like being able to have access to some Paramount films 45 days after theatrical release (A Quiet Place 2 will be first), The Challenge: All Stars being exclusive to the service and their Halo series that's coming. And for what I paid, getting a full year with no commercials was a pretty good deal. As I said in my original review of the service, I think this service has the best collection of stand-up specials only behind Netflix, which is nice to have as something just to throw on.