He has been very good about answering questions, he has provided good support even after the sale, and he is both friendly and knowlegable. And as for shipping the unit, it arrived beautifully packed, exactly on time, for a shipping fee that was more than reasonable.
The best part is that the proprietor of Metric Mind, Victor Tikhonov, isn't just a guy trying to make a buck - he genuinely cares about electric vehicles, and he actually drives one - I gather as a daily commuter.
I'll update this page as I learn more about the Siemens drive motor and inverter, the quality therof, and the difficulty of getting adapter plates made, but as far as customer service, they don't come better than Metric Mind.