I was always disappointed with my a/c too. From the day I bought it, it didn't seem right. Got it recharged and the guy told me that the a/c compressor/condenser...or whatever was on the small side for our raptors. After getting recharged, it was better but not great.
Then I started hearing a sound when I shut off the truck that sounded like a slow winding down of gears when I shut off the truck. Took it in and was told that my a/c compressor went bad! It had I think 10-15k miles on it total at the time!
Seems to me that the a/c is a sorta week point of the truck and is on the small side for our truck. Does the job but not going to be the greatest.
I have to say that my a/c has been much better and consistent since it was repaired. Then again...summer is coming and I get 105+ degree days where I am. The true test will be coming soon!