Pretty sure two NON-production, one-off cars that are over a year old and likely not iterations of production units in the least, being driven by two of the most aggressive drivers in the industry in arguably gnarly track conditions, driving over 100mph(as high as 126mph) for extended periods, and only breaking a couple belts between the two and one bad starter - a negative result.
The starter was a known issue of the past and addressed in production units.
Pre-production test mules haven't had any belt issues. Production units are speed limited to around 90mph. I don't think can-am or polaris would fair much better at those speeds. From what I saw, when the Speed was running good it was blowing by a lot of cars.