>That's really what I am asking. Without ever trying a grip, >it does not seem like it is more effort holding a camera in >portrait mode than landscape.
Have you tried it? It's a carpal tunnel NIGHTMARE. Look at the angle your wrist takes when you place the camera in portrait mode. Do you want to do that day in, day out, 40 hours a week? I don't shoot that much, but many pros do.
I know my hang goes numb in about 30-35 minutes of shooting my D7000 WITH the grip. Takes about an hour of straight shooting on my D800 without the grip. On the Dx cameras, it's never an issue.
>So is that the big win? It's >more comfortable to hold for long periods in portrait mode >(despite the added weight)?
For me, yes, it is that big of a win. The added weight means nothing as I am generally on a monopod for sports work, and for fashion work, I get mini-breaks where I am adjusting the model, or lights, or something else.
>Oh, for the days of good local camera stores, where one could >try things out....
My local Best Buy has everything I'd want except the pro bodies. Works for me.