Well, with high speed testing, it's not accurate to compare lab results with real world performance. the lab test is much more severe.

The unit pressures on the tire footprint are more concentrated on a 67" flywheel than on the flat ground. And the temperature effects (the big tire killer here) are MUCH greater in a room with no cooling air blowing past the tire.

If you enjoy sustained running at triple digit speeds, my best advice is "don't". But if your gonna do it anyways, your best bet is getting the highest speed rating you can afford, and keep an eye on your air pressure.

Of course, these are my own personal opinions, and not those of my employer (yada, yada, yada).