[pfhayes]

YC companies aren't "done" after 3 months. They keep building and growing for years to come. The 3 months is just how long it takes from first dinner to demo day. Companies of all types are typically able to show some kind of growth, traction, or progress in that time.

[pitchups]

Yes, I do know that. However, the point is precisely that even getting from first dinner to demo day in 3 months, will be much harder for "hard tech" companies than your typical web startup. Which is not to say there won't be any progress - but the real question is would there be enough time for the multiple iterations typically needed to get the most out of the incubation time at YC.