We've sold countless kits and never had a bad/ broken spring issue and have never seen one. The firmer springs were always considered ideal but optional. We saw the market demographic getting younger and figured a cheaper kit would sell better than a more expensive kit and offered our $30 kit in 05 or 06.
I don't think there is anything wrong with Intense' kit. I just have a hard time swallowing anyone telling me that their kit and the Transgo kit are the only way to go without elaborating at all.