I never noticed any drop in power above 80 mph in 3rd 4th or 5th gears. The only thing noticeable above 80 is that the wind drag becomes more noticeable... perhaps it just seems like the power is lower. On a long straight road without any other cars, I've run her up to about 120 indicated. I never hit a limiter, but it wasn't accerating very much anymore. The car accelerated about how I expected for it's pwoer and size.

Overall the car is pretty slow and not meant for speed. If I want to go fast I have my motorcycle. I only need less than 1/2 mile from a rolling start to get up to 160+... instead of almost 1 mile in the Accord just to get to 120.