I watched a review of a MB-D80 vertical grip for a Nikon D90 and one thing that they didn't like was there was no distinct "half-way" press to focus. They said you had to hold it roughly in that area, but it was very easy to over press and end up taking a photo.
Does anyone have one of these and can comment on what it's like?
Secondly, on eBay a genuine one seems to go for $125 or so whereas a Chinese version is around $56. Is there really a big difference between the 2?