Bike stiff : Powercranks X-Light

I'd used the last two month - ok nearly - to exercise with a piece of equipment called Powercranks X-Light. It's ridiculous expensive, heavy and awful looking! Assembling was straight forward and didn't result in any difficulties.
The Marketing f*gs sell it as:

"PowerCranks, when integrated into the normal training routine, allow the athlete to achieve more than was ever possible before. This one tool will allow the user to:

1. Train important muscles, undertrained in almost everyone (more)
2. Ensure your leg and core muscles are balanced (more)
3. Improve running and cycling speed/power (more)
4. Improve running and cycling technique (more)
5. Improve running and cycling efficiency (more)
6. Reduce your risk of injury (more)
7. Improve training time management (more)
8. Improve rehabilitation outcome after injury or surgery (more)
9. Increase your VO2max (more)
10. Plyometrics without the injury risk (more)
11. Other possible health improvements (more) "

The points listed results mainly from the fact that the two crank arms backward freewheel works independently and you are forced to synchronize the pedal stroke. Get it? This sounds "more or less" logic...

The first 20 minutes of training was:
pedal stroke -- pedal stroke -- *wtf* -- *laughing* -- pedal stroke*10 -- *cursing* -- pedal stroke*20 -- *more cursing* -- 5 minutes pedaling -- *pain* -- *cursing* -- 10 minutes pedaling -- stop.

After 1 month of training on the roller I came to the conclusion that it's just a waste of money and decided to sell it on ebay. My decision is based upon the feeling, that I am just one of those "mashing guys". Wanna say, my quads and gluteus' are used to do the job!

Thank you