The main difference is that the Schwinn pro has a chain drive, whereas the Lemond has a belt drive. The Lemond will give the better workout because you're forced to work out a lot harder. You MUST add more resistance in order to get the results, and when you do, you'll find the workout much more challenging. The Schwinn bikes have the chain, which actually can drive the speed of the wheel (which means you're actually doing less work... the chain does the work for you!).
I think any of the belt driven bikes can give a quality ride. In addition, you can spend more time working on your pedal stroke so that it's smoother, which means you can work on improving your ride.
This is a lot my own opinion, but some of it does come from the bike makers too. What I do like is that Lemond has a good maintenance schedule and are very proactive with problems and repairs. I haven't seen that from any of the other bike companies.
Don't cheat from now on. Go back to the RevMaster and do the ride again, but this time, if it's easy, add more resistance and maintain your speed. You'll feel it. If you don't, let me know.