The Weber Q series is popular because:
-It has a cast iron grate that, when preheated for a few minutes, will actually make a steak or burgers sizzle a little and put grill marks on it.
-It does well at lower temperatures for chicken.
-The bowl shape bottom facilitates having the drippings flow into a disposable pan.
-The bowl shape bottom is easy to clean by scraping the burned bits to the bottom tray.
-It comes in three sizes: small, medium and large. The small is perfect for a couple of steaks, some chicken parts or some fish.
-It is made out of sturdy cast aluminium, not sheet metal.
-It has good accessories available. The storage bag is perfect for containing the smell and BBQ bits when storing in the motorhome.
-Parts are readily available, if needed.
I have two. A small 100 model in the motorhome and a large 300 model at the condo.
That said, another fun alternative is the Lodge Cast Iron Hibachi. It is the right size for a motorhome, uses real charcoal and cleans out with a whisk broom.
http://www.amazon.com/Lodge-L410-Pre-Seasoned-Sportsmans-Charcoal/dp/B00022OK2A/ref=sr_1_2?ie=UTF8&qid=1344870684&sr=8-2&keywords=lodge+hibachi+cover