Going through months of research, having purchased Biktrix and other bikes, going through service requests and failed configurations (such as this tire issue), keeping in the performance and price points, I would recommend 2 paths:
1. Build your own: you must be willing to wait for shipping, do your own build, have it painted in some cases and doing the leg work - you can directly order the frame, motor and components through China for about $2k. There are thousands of distributors there using Bafang and other standard products and some can be ordered in a more complete state than others. This is what Biktrix, M2S, Surface and the like do. However, if you cannot or do not want to do this..
2. I'd buy from a large vendor who has local USA support - Yamaha, Trek, Giant, etc.. - but you'll have to pay.
As highlighted in many areas of the electricbikereview forums is that many of the current suppliers have poor or non existing quality business practices. A tire falling off a bike can lead to injury and death and should include litigation and a no hassle no fee return policy. But note, many of these small places make it cost prohibitive to return or fix something. I have personally wasted countless frustrating hours with support personnel whom a) cannot read questions, b) do not respond, c) do not understand what you're communicating, or d) do not know. I believe they do this 90% intentionally - as you are no longer important after the sale. Buyer beware. If you bought a motorcycle or car and the brakes failed, the tire fell off, the cables leaked, or were misprogrammed, etc.., there would be immediate litigation. I don't think these smaller companies care about it as some are nestled in another country and can quasi avoid litigation. With that there are probably others that do well. For example, I purchased a Juiced Ripcurrent S last year and found the product and support solid. Just didn't like advertised performance.
Example of china made
Hope this helps anyone.