Been using this pretty steadily for about three weeks now.
I have to finish up some trim and staining, but I was holding off until I knew the design was stable. Probably have about 8 hours of time on it now -- figure I've done 30 minutes most mornings, one hour this morning.
2mph is a bit fast, and 30 minutes is about all the time I can do basic stuff before going to my regular desk.
I slowed down to 1.6mph today, and was able to occupy 60 minutes worth of time (and even took a phone call from mom) while on it -- it's slower enough I can concentrate a bit more and do some more advance work then I had been at the 2mph pace.
The top got a number (4? 5?) coats of polyurethane. The dish towel is rest my elbows on comfortably when typing. Almost wanting a wing now for it so I could fit a full-sized notebook to my right.
One of the screws went a bit errant, but it did the job. Counter sunk on the top, with the counter sinks filled with polyurethane to keep the surface even. Every place a "surface" met I placed a strip of rubber gasket material, which was held in place by superglue.
That includes between the wood arms and desk, between the desk and top of the treadmill, here between the arms and the uprights of the treadmill -- I think that's really helping a lot compared to just hard surface to hard surface. Plus it let the screws and bolts really bite down when tightened:
And between the metal "washer" and the treadmill uprights: