There is alot reviews on YouTube about the Nikon D5100 and the battery grip upgrade/accessory. I was looking getting one before I do here's my question are they really worth it and what does the battery grip actually do for me? I know the battery grip makes the camera looks like a professional high end camera. Also, what manafacteur would be best to go with? Meike? Sorry if this subject has been brought up brought up over and over.