Using the TACX Fortius for about a year now. It totally kicks ass, literally. The VR modes are fair, at best. Where the Fortius shines is with the videos and catalyst courses.

The real life videos are great and they have some new RL videos where you can try to keep up with a pro team on some training rides. I have stages from the TDF and the Amstel Gold Race. I am planning on picking up a few more when the weather here turns colder (thankfully months away).

You can also use it in Catalyst mode which permits you to preprogram intervals or duplicate real course profiles. In fact, there are about 2 dozen real climbs (Mt. Washington, various TDF climbs, etc.) available free online.

Oh, the resistance unit is very realistic (well for indoor riding). Going uphill, it can simulate grades up to about 20%. But, if properly callibrated, the wheel may slip a bit as things get steep. Overall, its a great trainer.

A few nits though:

1) downhill the trainer may not register any wattage (this is apparently a voltage issue in the US with the resistance unit).

2) the Software is a little buggy.

Hope this helps.