Much of your decision will probably depend on how many days a year you will be living in your RV. Are you just doing weekends and a couple cross country trips, will you be a long-timer, or possibly thinking about full timing?
As I sit here in the living room of my 39' Montana FW I feel like I am in a small apartment. The living room/kitchen area is approximately 13'x20'. It would take a pretty large diesel pusher MH to have a living area that large. We can walk around the king size bed, there is a hallway closet that holds a side-by-side washer/dryer.
My point is, how much living space do you need/want? You can find some new model FW's in the 38' to 39' range that can be pulled properly/safely with a 1-ton SRW diesel truck. It still is slightly less efficient using a 1 ton truck as your driver when traveling and camped, but much easier than having a DRW 1 ton truck.
I think some folks are worried about learning how to drive and back-up a FW. It just seems easier maybe to learn how to operate the large MH. Just remember that you really can't back up a MH while pulling a car behind you, whereas you can back up a FW combination for 10 city blocks if you want to. Either a MH or FW you can practice and learn.
When traveling and I need oil changes and/or fuel filter changes it sure is simple having just a pickup. Generally I just drop it off at the dealer and wait or get a loaner vehicle. With a MH you have to find a garage that will do the service first of all, then with all your belongings inside your unit you have to worry about security issues in my opinion.
There are certainly tons of folks that love their MH's. But for us being full time and traveling the FW sure works better for us.