Hi there @PhiloFarmer.
I have no doubts that I will enjoy whichever model I go with!
I have had a good deal of experience with the 500C/M, and I have always been amazed how easy it is to support and use - the balance and size is excellent. Not the heavy, unwieldy beast that some people think it would be when they see it.
And, yes, I too love the manual winder. Exercise for the fingers, for the ears (it sounds so reassuring) and for the soul. I don't know how you could forgo this satisfying exercise and go to a model with a motor winder such as the 555ELD??
One other thing that I am noticing here is that many of the respondents have multiple Hasselblad bodies - This wasn't something that I expected. I'm not sure that I could share my attention around - i.e., be "polycamerous" !!
... MomentsForZen (Richard)