Comparing a stationary bike to a PT equipped road bike

I've had to replace the flywheel of a cycleops 300pt. Now I'm not so sure if my setup left the bike with too much resistance from the nuts and screws that hold it in place. With resistance at the lowest setting, the wheel isn't completely "free" where it spins around for several revolutions. I goes around maybe 3 times tops.

I get this reading when I am testing it out:

20mph/80rpms/80-90 watts...

This is the lightest (no resistance) setting possible. If you were pedalling along to these numbers, what would it "feel" like? Is it completely flat or is the a +/- slope?

..not right. Just moving the pedals around seems around 75watts in my limited experience. 20mph is more like 150-200 on a flat surface, given my weight, etc.

Interesting indeed...When I thought I had the nuts on too tight, I was registering 150 watts for 20mph/80rpm. There was definitely some resistance. When I wanted to recover, I felt that this was how fast I needed to spin the wheel in order to not feel too strained. It feels much better now that the wheel is "free-r".

So perhaps the way I have it now is like a high gear with a negative slope...But even if the speed is off, power is power, so I am exerting the same amount energy on either bike.