The gbb version is really good out of the box but I did some upgrades.
PDI 6.00 inner barrel
WII TECH aluminium nozzle
WII TECH Rubber Pad
Maple Leaf Hop Up 60°
Running the TM on Black/14KG gas at 1.4J with 0.32gr bbs.
I would highly recommend to upgrade the nozzle because the stock one breaks very easy.