Actually Nikon is probably less than happy that people(me for example) suggest skipping the expensive 1/2 metal and 1/2 plastic grip for $300 and get the $60 all plastic copies. I have them on 3 cameras from 3 different makes and they all work great, have been flawless and still looks and perform like new.

The AA batteries have the one advantage, they can be purchased in a pinch anywhere you might not have access to a charger. Otherwise, the original battery lasts longer, has higher burst current and charges faster than AA lithium cells and lasts much longer than AA Alkaline non-rechargeable cells.
There are 3rd party batteries that replace the Nikon with slightly higher performance but there are also knockoffs that are not very good at all. So for batteries it is best to get advice from someone you know who has had good luck with a particular brand. I have 3 Nikon batteries and 2 Delkin and the all work well and have for several years. It is nice that two of my cameras share the same model battery now.
Stan
St Petersburg Russia

Visit my Nikonians gallery.