The prices for me was a bit of a special case since both @陈小杰 (Xiao-Jie Chen) and Yi Chen had gotten interested in the case. I paid much less than I would have, thanks to their kindness and care. But normally a new motor would be $250, a new controller $280 and new batteries would be $588. Good to know though is that Yi Chen of Rockwheel Store normally leaves an informal warranty for a year, 6 months for batteries. You'd have to send back the parts, but in some cases a video demonstrating the fault can be enough. Much of that depends on what part and wether they want the part for testing and control.
Much of my woes about cables and connectors seem to be ironed out. The new connectors look way better than the old, but I will follow up on that when I get the parts.
The early criticism was burnt out controllers after just a hundred kilometers or so, I don't know what that was all about. My problem seem to be the gyro, but temperatures in the controller have been consistently low or even remarkably low. If you go slow uphill for a stretch, it may rise as high as 70°C, but as long as you have some speed the cooling system is remarkable. Going at a slight elevation at 15mph I never topped 40°C on flat ground and 20mph I never topped 36°C. At times I think the cables heated up some, but I never made any persistent hill climbing like what got @Marty Backe's ACM fried, so I don't know how bad that would become.
Physically there i a choke-point for the cables on each side of the board leading down to the battery compartment, and of course the choke-point of the cables into the motor. I don't think that is a big problem as long as you don't go crawling uphill for very long, since the choke-points are physically inside the heat-sink.
So in reliability most problems actually lies in the shell design. Part of it are that it could be thicker in places, part of it are tight tolerances in the heat-sink, part of it are screws that could be more substantial - but the screws for connecting motor and shell are very good. Those choke-points I mentioned are overall unnecessary, there are a few simple choices that could have been made to move the water-proofing from "OK in rain" to "OK to use your garden hose". The board could have been laquered to avoid problems with condensation. And simple silicon-liners in the covers and around the board housing, would basically have made it more or less waterproof. I think it would be relatively easy to fix yourself if you're willing to open it up and carefully use some sealant in the relevant places. The battery placement helps, since they're basically water-tight to above the axle.
Concerning serviceability, the covers are very easy to open up, while the board is rather more inaccessible. The connection between board-cover and heat-sink is a point that requires real care, as it is far to easy to break something. Getting the wheel out to fix punctures is somewhat of a pain, as it requires removing the whole board and heat-sink assembly with all the cables and then loosening the screws in the shell. When you actually get it to loosen up, it is simple to do the rest. The method of pedal assembly is very good, and not very likely to loosen by vibration. As I understand it, it is reminiscent of the KS-solution with a top and bottom part of the assembly connected by two fat and long bolts that force the connection tight.
So what is the conclusion?
Well, if you're willing to learn how to do the work yourself, it's a wheel as good as any. But servicing has a slightly higher learning curve than for example GWs wheels. Spares (any spares) can be had through Rockwheel Store, just ask Yi Chen about what you need if you don't find it in the inventory.
I think I was a bit unlucky with my motor breaking down, and I can't escape the suspicion that the interference of loose metal in the wheel somehow affected the board and made the gyro go crazy. I think it's a fluke though, and not a fault you should expect to happen to many wheels. In fact Yi Chen said that through the years he's managed Rockwheel Store, this was a first.