I was just working on one of those a couple of weeks ago. It seems unnecessarily complex for the DIYer, and no matter how neat you are, having all that wiring tie-wrapped to the outside of your bike gets messy. And that package doesn't seem to include the battery (48V SLA I think) or charger.
I had little contact with the electronics, I was mostly concerned with getting the trike in rolling order again. Of the two I worked on, one had a broken on/off switch connection that didn't seem repairable so I bypassed it for testing.
The motor and related components seem durable, both the trikes I worked on had been sitting out in the So. Oregon weather for a couple of years.
I'll burn that bridge when I come to it