It never ceases to amaze me that contractors will micromanage every dollar and hour spent on jobs, but not salespeople.
When it comes to employee pay schemes, if it sounds too good to be true, it probably is. My basic rules of people management are to pay people well, hold them accountable and practice sound management techniques.
Employees will forgive you for all kinds of management mistakes but messing with their pay is an unpardonable sin. It is also important to remember that employees are employees-not owners, not vendors, not entrepreneurs, but employees-and no system will turn them into owners. Also, any pay system must be perceived as fair and both parties need to win.