Only the Howitzer has quick repair . The other two light tanks only have mobility repair . <| sep |> I ' m not sure about the differences between the two bodies focusing systems , but I do know that sometimes the center points are dual cross type IF the lens is f 2 . 8 or greater . Meaning they have a greater sensitivity and are more likely to lock focus in low light . For this reason I typically do my night clubconcert photography with a 28 mm f 1 . 8 USM mounted on my 7 D locked to the center focus point . Even still there are times where I have to prefocus by aiming at something with contrast edge of the subject instead of the center and that usually gets me good results . Also , I try to stay away from shooting wide open , especially in low light . My camera is already having difficulties focusing , so I give myself some leeway and sharpness by sticking anywhere between f 2 . 22 . 8 . Hope this helps ! Edit Here are some examples of my shots .