The Zeikos ZE-CBG50 battery grip (sometimes referred to as Flashpoint?) is an excellent alternative to the Canon battery grip that is priced $100 higher. While I haven't seen the Canon BG-E2N grip, my guess is that the major difference between the Zeikos and the Canon is that the Canon has a weather seal around the battery door (The new E2N model claims to have it, and I didn't notice any weather seal on the Zeikos.
There is a good video review of the Zeikos if you search for ZE-CBG50 - the review [...] and it is syndicated throughout other photography websites. In short, you won't be disappointed with the Zeikos battery grip as it has a shutter release button, a mode dial and the AE-lock and AF selection point buttons. The older model CBG40 did not have the mode dial I believe. It also has a rubber exterior for your hand that is comfortable and is nearly identical to that on the camera.
Zeikos ZE-CBG50 should be on every serious photographer's camera body. This is a high quality grip. I would love to say that it "should" be in ever photographer's bag, but of course, in reality it depends on what you shoot.
I found myself reaching for my camera more since I got it a few days ago, just because it is so much fun shooting in all orientations so freely. Does it add bulk to the camera? Of course! But if you're going to complain about that, why did you buy a DSLR in the first place?
Besides the obvious of having a longer battery life (definitely a plus) and easier portrait orientation shooting, I find the camera much better to grip and hold with the grip on. All of the buttons on this Zeikos grip work with no hassle.
I guess a person can have a little more ease of mind if they purchase the genuine Canon battery grip, but for less than half of its cost, you can buy this 3rd party Zeikos grip and have the same functions.
A winner? Definitely!
I would recommend you to buy Zeikos ZE-CBG50 from this site. Trusted site!