I just picked up a Q200 off CL for a good price. I was really looking for a 120 as it was to be used for camping out of my boat as well and I wanted to try and keep it in a hatch. It's primary use will be tailgating and for that and use around the house, I was immediately pleased with the extra grill space. I think unless you are really strapped for storage, or need the lighter weight of the 100/120, you will be happier with the Q2**.
I will add that by dumb luck, I might have stumbled onto a good compromise....I added a thermometer to the Q200 I found on CL and now effectively have a Q220 without the larger higher dome lid, saving a lot of size and some weight too. I think Q120/220 are more appealing to people due to the tables and the thermometer, and not necessarily for the increased dome height. The 200 has the tables so adding the thermometer for $12 gets you a nice little package.