One thing..they both need oil changes and yes, a diesel takes more oil but the change lasts for 15,000 miles whereas a truck is more often.
RE: having to disconnect the car to back into a spot. It's not the least bit difficult at all. Actually, we prefer backin spots as they're usually more private.
RE: a truck doing off-roading as easily as a Jeep. Depends. We've witnessed trucks being too wide for the trails. There are some trails in Silverton, CO that a truck couldn't go because of the width and the turns needed.
Naturally, we don't do 4-wheeling with our motorhome. We park it off one of the gravel roads and use the Jeep. However, our motorhome has gone on long drives of gravel roads but it's not a rock climber. :)
Bottom Line: There's no perfect answer. You'll just have to pick and choose what's more important to you.