If resale is an issue, the softail wins. But in reality comfort, style, etc. should be what makes the decision. I had my heart set on a RK and when I went to buy, I sat on one and also on a Heritage. The Heritage picked me and that's what I park my ass on every day now.
As for ride and comfort, I've got a fatass at 270, but my bike is pretty comfy even with the factory seat. My OL and my girlfriend both love the stock passenger seat so there are no complaints there.
I have alot of friends with the RK and it is the king of comfort -- maybe someday I will get one, but I love the bike I have now.
You should really go the rental route and ride the crap out of it whenyou have it. Ride it around town and all, but you should also get on the highway and go 50+ miles straight to see if you are comfrtable. I rented a Deuce when I was traveling a month ago just for grins and it was a blast to ride and comfy for me, but not as nice for the passenger.
Even if you spend a few hundred renting bikes to try them out -- it could really be worth it over the long haul. Also, if you buy from a dealer that has a rental fleet, they may be willing to let you rack up some significant miles for free to get the sale.