Pros: OEM - what else can I say

Cons: Awfully expensive

Pros: Good battery life, hands down.
Usage data in the battery including rechargeability is quite useful.

Cons: Price, as usual with Canon accessories.

Other Thoughts: I've used third party batteries in my cameras before, they don't have the longevity... you get what you pay for. I've had two of these Canon batteries since January 2009 when I got my 5D MKII, and just NOW one of them shows one notch less in recharging capability. It still works great, and it took almost 2 years to even start degrading. Don't mess around with third party stuff. You spent $2500 on your camera, use the battery that was designed for it. That's NOT just paying for the Canon name, you get a more reliable battery. I just think Canon, after ALL of the 5D2 and 7D sales, should be selling this battery for $39 tops. I'm just sayin...

Pros: Battery lasts for quite a long time and has a seemingly low recharge time. Works perfectly with my 7D.

Cons: You're paying for the Canon logo. You can find other batteries of equal quality for a much lower price.

Pros: camera tracks battery performance, fast charging time, long life

Cons: none

Other Thoughts: I have the vertical grip for the 5d mkii (BG-E6) and have been using it with six 2650 mAh NiMH rechargables for several months. But two LP-E6's outlast them even though they are only 1800 mAh. The AA's will be great for spares, but the LP-E6 is the way to go whether you have the vertical grip or not. Great product

Pros: *Works with 5Dmk2
*OEM battery

Cons: *Price
*Availability

Other Thoughts: These things seem difficult to find. Almost always out of stock from reputable online stores and in turn seems to be driving the price up.