You can get leveling systems added to 5th wheels that will work just like the ones on the MHs. You will need to level a 5th wheel just as often as you have to level a MH from side to side. Don't believe the salesman especially when it comes to how big of truck you will need for towing.
A generator is a nice feature for the same reasons you used one on the MH. You do give up some storage space but remember you will have lots of storage in the bed of the pickup that you didn't have with the MH. There are boxes you can buy to fit in the pickup bed to provide security but allow easy use of the hitch.
5th wheels can now be setup with all the automatic goodies you find in MHs which makes them just as easy to setup when you get to your destination.