I will leave the engine/trany thoughts to others a sit has never been so bad that we ever felt change was needed!
But that is often due to what we have each driven over the years and how fussy we are about ride and drive.
My experience has been farm trucks first as I learned to drive and then line trucks, often with poles on trailers behind. My standards for what drives okay are far broader than folks who find an RV the hardest thing they've had!
If you learned to drive a pickup with a 1000 pound steer in the back, RV are a piece of cake!
But if you want go tet down to looking at the details of an RV that don't show, this is a site that I find great as it is interactive and we can look at all the parts and where they put them without a lot of trouble. It also gives a parts list to get lots of detail on tank size and locations.
Note that it is filed by year, model and then may also need to know if it is early or late year builds as small details are often changed mid-year. Serial number with 7th digits of 1 is early or 2 if later build. Not the vin, though! Serial numbers should show on label near drivers left side!