The Esc used are Hobbyking F-30A all B-FET. I re-flash with BS-Nfet.hex Simonk firmware.
Start to assembly on kit. flight control is APM 2.5.2 with power management board
Almost finish , the total weight not including battery and gopro gimbal is 1434 grams.
So AUW will be about 2.25kg for 1 pask of 4S 3500mAh or 2.7kg for 2packs of 4S 3500mAh.
It is OK for this size 620 M2M with 15x5" props.