I don't have UT99, so I can't compare. I've heard it's like UT4, which I didn't really enjoy all that much. So put me on the Quake side of the Quake/UT fight, I guess.

And I could never get into CS.

UT was better than Q3 - wider variety of weapons, more fun game types, better maps.

But Q3:TeamArena was massively overlooked. It added megatexture to Q3, had massive maps, cooler weapons, and a better aesthetic.

I still go back and play Quake 3 Team Arena with bots from time to time. Still one of my favorite bot experiences.

But Q3 had advanced movement, a stronger modding scene, and a grappling hook (sort of).