I "camp" (I use the term loosely) annually at the Pocono Raceway with friends. One of them has a Weber Q, I have a Coleman Roadtrip. Cooking steaks, chicken, burgers, sausage, brats or any variety of meats there really isn't any difference between the two performance-wise that I can tell. The Weber feels sturdier - the lid is heavier (which breaks the hinges with a lot of use).
I hook my Roadtrip to my onboard propane tank, but it works just as well with a cylinder. It folds up small enough to store in one of my side compartments.
I have a Weber Platinum at home and it's hands down the best grill I've ever owned. It's almost 20 years old, and other grills have come and gone in that time. But for portable stuff, I wouldn't pay the Weber premium. Just my opinion.