Jer, about six months ago I purchased the hoodmanusa powergrip for my D70. Considering there are only two aftermarket grips for the D70/D70s, and neither one of them are made by Nikon, you dont have much of a choice.
The copy that I received, fits my D70 very well. It does feel plasticky but when you place the 2 ENL3 batteries in it feels more solid. Having 2 batteries in it ofcourse extends the shooting by a factor of two.
I purchased this for 2 reasons. One, because my hands are large, and this grip allows the camera to feel more comfortable in my hands. Two, I can use AA batteries as a backup.
As for the vertical shutter release, I personally do not use it as the IR extension that connects the powergrip to the D70 can easily be knocked off, and besides, looks ridiculous.
If you want a grip for the D70, the hoodmanusa product is the better choice of the two. I have seen the other brand which at this time am unable to recall who makes it but found it to be flimsy, and did not fit as well.
Hope this helps.
Paul Tchiloyans