My initial complaints about the ePure Race are unchanged from my pre-purchase due diligence:
It's heavier than I would like. Whenever I roll the bike around without the battery installed I think, “That's the bike I want!” As well as being lighter, the center of mass moves down and toward the rear.
The clutch is buried. Watch EM's video on replacing the clutch pack. I understand why it is the way it is, but no ICE motorcycle is built this way. Moreover, GasGas, Yamaha, and Mecatecno all exhibited electric trials bikes with an accessible clutch.
Parts are expensive. Have a look at my page about US Parts Pricing to see what I mean. Furthermore, part numbers should not contain the letter “O” because it's easily confused with the number zero.
Wiring and connectorization are a mess. This probably offends me more than anything. Again, I understand why it is the way it is, but Yamaha will do it better.
More than a year later, I have a few additional gripes:
Factory support is poor. Of the 4 ePure Race bikes I know about, 3 had an early motor or battery issue. They each took months to resolve. In the case of my personal bike, the prior owner repaired the battery himself even though it was under warranty.
Motor controller is locked. This is not unexpected. No OEM is ever going to make it easy to reprogram their ECU or motor controller, but the Stark Varg model of giving the end user a way to tailor the power delivery is the future.
BMS info is not available. We'll see about that! The end-user must be provided with a way to query the BMS. The US trials market is too small and fragmented to return your bike to the dealer for anything, much less for a periodic battery health checkup.
Can't park on a slope. When in a low gear, an ICE bike generally won't roll away. Conversely, when you select neutral, an ICE bike is much easier to push.
The single-speed gearing is a double-edged sword. Yes, the very wide speed range is often really useful - you are never in the wrong gear. But I often feel it is geared too tall. This manifests itself by generating too much speed and not enough lift. Perhaps a more skilled rider would not find this a problem?
Would I want it as my only trials bike? No. Is it a good trials bike? Yes.