I have a 2000 Monte Carlo SS that hesitates when I'm on the open road and accelerate slowly when the rpms are around 1800 to 2000 and I'm usually in overdrive. If I push the accelerator to the floor when it is hesitating the tranny changes gears and the hesitation goes away. It does not happen from standing start.

I've check the fuel pressure and it is okay. Has anyone else had this problem and is it related to the transmission or something else?

You might try getting an induction service,a/k/a fuel injector cleaning . The intakes & injectors tend to carbon up on G.M products.hope this helps