I got the LESU Caterpillar 374 excavator.
I would recommend replacing the brushless ESC's that control the drive motors. I couldn't figure out how to program the included ESC's to remove the brake function before going into reverse. I don't think it's possible to remove it on these ESC's. I bought some of off Ebay that should go right into reverse, I'll see when I receive them.
Also bought some fluid filters from Magom HRC and some filter assembly that is ran in real equipment. The kit doesn't come with a filter.
I am in the process of taking apart some of the preassembled pieces and loctiting the screws and making sure grease is where its supposed to be.
more pictures here
https://imgur.com/gallery/nS8qmLY