I recently purchased a JG m4 CQBR and this was the stock motor in the gun.
I recently decided to install an AMP m120 spring into the gun. At first I was a little hesitant because i'm not a huge fan of JG, but to my surprise, this motor performed very well.
It is a torque up motor, so the rate of fire isn't the greatest, but the trigger response is AMAZING. It felt similar to the old school Systema Magnum Motors (in terms of trigger response) and I was getting about 15 rounds per second (900 rounds per minute) with a large type 9.6 volt.
If you want good trigger response and aren't TOO picky about rate of fire, this is the motor to get. Do not let the name fool you, this motor performs just as good if not better than the TM EG1000, the CA Torque Up Motor, and even has comparable performance to a Systema Magnum Motor (old type, I've never used an A to Z motor). I personally feel like it outperforms the Hummer1300 Max Torque motor, but again, this is just my personal opinion.
Overall......great little motor!
Good Trigger Response
Can pull an m120 with extreme ease
Decent Rate of Fire ~15 RPS with large type 9.6 volt
None that I can think of, other than the rate of fire isn't the greatest.
Get this motor!