Originally Posted by Happy Feet

I get it.
However, without a power meter one does not really know how many watts they are putting out. All they have is perceived effort.

I would posit that a rider on a mid grade bike on a set course, compared to a rider on a race oriented bike, would have a higher perceived effort because, all other things being equal, they would be putting out more watts. The race oriented bike rider has an advantage in terms of effort to speed ratio and would have to increase his/her effort to match that of the mid grade rider.. Ie. they have to compensate for the competitive edge the bike gives them over the mid grade rider.

If the goal is only exercise, why pay more for a competitive edge you then have to compensate for by doing more work.