The only problem I have had is that by being DM I have a definite preference for how the game is run.
So my difficulty has been finding DM's who run games in a way I can like.
The only exception I have to this is when my kids DM me. Since it is a learning experience, and they want me to tell them my opinion, I play in their games.
Which are actually very good on ideas. They just need to learn to control themselves and not speed up our progress, etc... to get to the "good parts". Plus they are getting a good handle on balancing encounters, etc... So eventually I will enjoy their games a lot.
I am very much a "don't let the rules get in the way" kind of DM, so when a game session bogs down because of strict adherence to the rules, it really irks me. I find my enjoyment for 3E goes way up when we ignore AoO micro management of the combats.
The only AoO I like is for when they run away, and I don't allow a feat to negate that AoO.
My kids like them, so I spend a lot of time grinding my teeth waiting for battles to be resolved, at higher levels.
I never had your problem with monsters. I made myself not memorize any of the monsters. So when I do remember something I'm OK with it because I can mark it off to hearing things in bar room stories, bardic tales, etc....
So those are my "issues" as a result of being a DM so much of the time.