The Canon BG-E9 Battery Grip is the proper battery grip for the Canon EOS 60D DSLR.
Generally, Canon's Battery Grips are similar to each other and in many regards, the BG-E9 is no exception. Therefore, this review will sound similar to the other Canon Battery Grip Reviews on this site.
The nice thing about Canon DSLRs without a built-in portrait/vertical grip (all non-1-Series bodies at this time) is that they are small and light. The big downside is that these bodies are not comfortable to shoot with in portrait/vertical orientation - especially for long periods of time. Thus, Canon makes Battery Grips for all of their non-1-Series bodies.
To install the Canon BG-E9 Battery Grip, the LP-E6 Battery is removed from the DSLR and the battery door detaches. The BG-E9 slides up into the battery compartment and locks into place via the tripod socket screw on the BG-E9. The BG-E9 provides its own tripod adapter threads - this functionality is not lost.
The BG-E9 holds two Canon LP-E6 Batteries that deliver double the number of shots or video time from the DSLR. Alternatively, use 6 readily available AA batteries in the included Canon BGM-E9 Battery Magazine. The BG-E9 will function fine with only one LP-E6 battery - a second LP-E6 battery is not required.
The BG-E9 is nicely built - it integrates especially well to the 60D body with very little flex. The batteries loading from the end of the BG-E9 grip and oriented in line with the grip allow a less-squared and notably-better ergonomic design than the previous battery grips with their rear-loaded batteries.
In use, the BG-E9 makes portrait/vertical shooting much easier and more comfortable. I can feel the difference in my arms and shoulder after even a moderately long shoot. And I can hold the camera in vertical orientation a little steadier in this position.
Overall, I think the Canon BG-E9 Battery Grip is very useful - a nice-to-have accessory.