I've got the Q220 (Q200 with Thermometer) and am a HUGE fan. The Q120 is smaller so I don't think I would sweat the 8500 BTU rating, BUT the Q200 is just as portable as the Q120 and the additional grill size will come in handy at tailgates. I've cooked 14 hamburgers (smaller sized) and 30 hotdogs on my Q220 at one time and the cast iron grates are killer.
Spring for the folding table that goes with it so you don't have to worry about finding something to sit the grill on.
Pat