I got a Q220 as a 70th birthday gift, specifically for use when out in the RV. I hardly ever use the behemoth Charbroil on the patio any more, unless we're cooking for more than the two of us.
The ONLY negative is that it's about 0.7" too tall, with the lid on, to go in any of my MH's stow-bins. Since it's all of a 20-second job to pop the pins out and separate the lid from the body, that's just a minor inconvenience. I have more stow-bin space in the Georgetown than I know what to do with, so putting the lid in one bin and the rest of the grill in another isn't a problem.
I wasn't comfortable with the idea of a 20' hose tapped in upstream of the RV's regulator and carrying bottle pressure to the Weber's regulator. I'd also seen a few posts that suggested the big regulator in the RV's appliance circuit wasn't sensitive enough to regulate the Weber's relatively low flow rate.
I chose to go with a 10-pound portable bottle and chose a "squatty" that has the same base-ring size as the 20-pound bottle. I got a CW "base stabilizer" and bolted it down in a stow-bin. When we're travelling, the bottle is securely held by the base ring, with a bungee cord through the handle to an eye-bolt on the bin wall. I usually keep the bottle about half full, so it's easier for an old fart like me to lift it. With both the base and handle of the bottle attached to structure, I don't think deceleration loads would be enough to cause a problem! It's only about 2" from the bin forward wall.
I don't have the rolling cart (yet!), but it's no big deal to get the Weber out and set up on the CG's picnic table, particularly if I leave the C-I grill plate in the stow-bin until I've carried the aluminum body to the table.
We aren't BBQ purists, so I haven't used charcoal for donkey's years, even at home, so not having a fire-box base in the Weber isn't a big deal.