They are different animals. Each has their advantages and disadvantages. For most it boils down to personal preference.
As far as setup goes, you've already got an understanding of 90% of what you need. Hookups are the same. Leveling a trailer is not a big deal. Backing up with a trailer takes some practice but is not that hard with a spotter.
You will not have a wobbly ride towing a trailer. Properly set up and having an adequate tow vehicle, you will have a great towing experience. I won't say it's as easy a driving without a trailer, but it's not hard either.
We have 2 major reasons for towing a trailer vs. a drivable RV.
1) You don't have to drive it every where you go. Unless you get a large Class C or a Class A that can tow a car, every time you want to go somewhere you have to break camp and drive the beast everywhere.
2) A trailer is very easy and generally inexpensive to maintain. No motor to maintain, no worries about how long it sits without running the engine, etc.
3) I said 2? Anyway, I can and do drive the truck daily and use it for more than just the trailer. A class C will just sit when not being used.
