it's good, i find it very useful. adds a significant amount of weight, but I myself find it better w/ a bit of heft. it has a shutter, front and rear e-dials, a green button, AE-L and EV compensation button. I find the thumb controls (rear e-dial, AE-L and EV-C) are a bit hard to press, but i think they made it that way due to the sealing, and it can or might be pressed while in normal orientation (i have pressed the green or shutter released on the grip while viewing pics by accident on occasion)
another annoying thing w/ it is the fact that it only holds one battery. so if the battery on the body dies, you gotta take out the grip to get to it. (I have it set to use grip power first, then body) I do like the sd card and remote control f storage.
overall i am happy w/ it. the extra weight is a welcome one..(for me)
to answer your question...the e-dials will be the same as you set them on the body.....so if u have the front e-dial set as Av on P mode, then it will be the same on the grip..other wise it will be the default.....on both ends...(front e-dial = shutter, rear e-dial=aperture)