CSO said:
How useful is this winder? Does it really provide a firmer grip of the body?
I have found the CW winder very beneficial. First, I find it very ergonomic. Its design allows me to handhold my Hassey, even with a 250mm lens - albeit very fast speed in blazing daylight. Also, I like the features it offers - the IR remote, continuous shooting option (admittedly I have never used this feature), and the multiple images feature (easy way to make double/triple/quadruple etc... exposures).
Also, unlike wazza, I have never experienced a single misfiring. Every pic taken on my Hassey has been with the CW attached. I do all my studio work with it, I travel with it (it actually makes travel easier IMO), all my location shots, even shots taken on a tripod (with the IR feature).
Do I really need it for portrait type shoots or it is something that will simply add bulk to the system with no real advantage?
No, I don't think you really need it for portraits. It's a nice to have. I would check out the features and visit the local camera shop and feel it in your hands. As for advantages, only you can determine that.
Regards, Art.