I struggled with the same questions when I was shopping for my families RV.
We ended up getting a MH and really enjoy it.
Mine is 32' which seems to work out well...big enough for the 5 of us, but small enough to go most anywhere (the National Mall, Glacier Point, Hollywood Blvd, etc). For the most part, no need for a car.
We looked at 20 different MH's and found that the ones with slides, while great parked, where no good for the people in the back while traveling...hard to see the country with a wall in the way.
We have pulled my 20' boat to the Keys many times with no problem.
The last trip, we rented a car while we were there, that worked out great for us.