I still weight train a few days a week and always finish with a cardio spin session. I do intervals and get a great workout in a short amount of time. The bike can be set up reasonably close to my road bike and I have seen great results. During poor weather I regularly attend the classes as well. Overall, I think it has increased my strength and endurance...

The Kaiser bikes at my gym have cadence and power meters which will show your averages after each session.