Interesting point Mike. I guess if you need instant mirror return in a Hasselblad grab one with
motor drives are the way to go. I have a couple of 553 ELX bodies that I use mainly for portraits. I can see their advantage too for weddings and such. The full recycle time on a 553 ELX working even at slower shutter speeds is pretty fast to avoid taking my eye out of the viewfinder if I'm using it at the time.
I liked trying out the 6006 and the 6008 although I didn't have any great love for the handle on the right hand side. That struck me as being kind of flimsy if it got smacked and it might snap. But I don't know for sure. I suppose again, it really comes down to personal preference.