Been running mine 14 months now, 48v @15amps, (max amps can be set from the panel), no problems. Dismantled and greased once, I made the tool to remove the chainwheel. Otherwise regular tools. The motor shaft is supported at it's outer end in a needle roller bearing located in the outer case. This is quite small and could be overlooked when greasing if unfamiliar with such things. It's a single stage reduction, single helical gear with appropriate thrust bearings. Overall an excellent unit, suits my use perfectly, that it may not suit others does not make them wrong or misguided.
Some observations, A sign that greasing is required is a chattering noise when pushing the bike backwards. The original grease was a bit sparse, packing with good quality Lithium grease has transformed the running and all but eliminated the 'back chatter'. The now well packed gearcase may need a breather pipe at some point.
The response on the pedal sensor is adjustable on the the panel from instant to a delay to suit you. I like instant but take care if pushing the bike with power on, any turning of the cranks by chain drag or catching on something will cause the bike to leap forward ,so switch off, or one finger round the brake lever every time. A good point is instant cut off on both brakes and pedal sensor. There is no over run at all. The motor,controller and all wiring plugs are waterproof ,don't ask how I know this, just read the instant response bit again.