i think this warrants a good discussion, and will add a few myself.
i am performance based pretty much. we have a system that works well so far. i am a crew leader and get payed a certain percentage of each job, minus labor and materials are shared costs. this gives a pretty good reason to get as much done as possible but do a good job as going back on a job only costs us money. well, lost revenue at the very least.
we pay our labor by the hour so when you have bad days due to whatever, you make less but they always make the same. i was thinking about implementing a percentage system(vary with experience and performance in amount per individual) for them too, but i know it would be very hard for some to choose it as some paychecks really might now be that great. adversely, some would be very good.
i am sure it could be shown to them the advantages of it, fut still then i am pretty sure they would not go for it like they were getting screwed or something. you know how these guys are. we are however are known to be fair, respectful and generous with good employees.
this would be a great way to control labor costs better and i think with motivation these guys might actually make more if they just work a little harder and smarter. this way they can directly see the benefit.