Are you running the demos under the same settings?
Did you upgrade or clean install?
Also, you wont get the same amount of FPS when playing the actual game, as you would watching the demo. You could be playing a different level that requires more CPU, memory bandwidth, etc...You cant compare demo to actual gameplay, since the chances of you having the same references are minimal at best.
I cant tell you if your 80-90 FPS is good or not, since I dont know the circumstances in which you were playing it.
The real question is, are the games playing alright? Are you enjoying it? If the answers are yes, then the game is serving its purpose. If not, post the problem, and we can probably help.
I got it now.....nevermind
Someone else told me that around 80-90 fps was the default for play, apparently you won't notice a difference if it's higher, i did change mine to 125 fps by typing "cl_maxfps 125" in the console. Now it runs at 125 and i can't tell any differnce between 90 and 125. Thanks anyways.