Strengths:
-Can Bulky, the grip has put on the strap is handy
-Rest Relatively fast a cold or hot
-The Supplied remote has a locking catch, which is very convenient for laying B (Bulb).
-For Those who use a grip on D3100 / D5100, a cable is provided to connect the GPS module to grip the trigger because it uses the plug normally used by the trigger grip of the cable.
Weakness:
-One Can power hungry
I highly recommend it.