My gait on the treadmill is pretty consistent, cadence stays pretty close to the same regardless of how fast I'm going. As such, my watch matches the treadmill almost exactly at 6.7mph. Any faster and it underestimates increasingly as speed increases.
As far as feel, I have run on a LOT of different Life Fitness treadmills, and all of them have been pretty close to perceived effort, and a bit slower than I can do outside with the same perceived effort.
As far as feel, I have run on a LOT of different Life Fitness treadmills, and all of them have been pretty close to perceived effort, and a bit slower than I can do outside with the same perceived effort.