I've experienced a few of the same traits mentioned already--low power with the 4-cylinder, unremarkable gas mileage.
Some problems I've had include:
-Third door latch broke twice. Luckily, both instances were covered by warranties. Dreading reccurence of problem, since warranty now expired.
-Lights (headlights, dash lights, etc.) flicker off periodically at night. Possibly alternator/voltage regulator problem, but dealer service department couldn't catch due to intermittent nature. (Anyone else have this problem?)
-Lately, after about 38k miles and 3.5 years, engine now periodically loses power after I run the ac, and step on the gas. Not very comforting when the light turns green, or when I'm trying to cross traffic! (Anyone else have this problem as well?)
-Service Engine Soon light comes on intermittently now. Again, dreading the hassle and expense of taking it in for servicing.
Sometimes I wonder if GM did too good a job designing their products to fail prematurely, so their service dealers can get revenue. After good experiences with Honda vehicles, my confidence in GM is not very high.
I have had the issue with the loss of power after running the a/c for just a short while. Yes it is just a temporary loss of power, but still not what you would like to happen in traffic. Truck has 74000 miles otherwise trouble free. Any suggestions on what might be the problem.
I'm sorry for your mishaps, but I haven't had any problems with the truck. You should of went with the 4.3L and there wouldn't be any lack in power.