From the service side, precor treads are so so. Their ellipticals are great...the 546 and 556 have been a staple for awhile now....hell, there are still gyms that have the old school 544's on the floor.
As far as treads go....you get what you pay for. think of it as a car....its a big purchase......dont expect to drive cross counrty in a $300 car you bought at a gas station. Same thing goes for a tread....spend the extra $$$ to get something that isnt going to break down and die in a year or two
whatever you buy....cheap or expensive....MAINTAIN IT!!!!! decks and belts need wax (most do at least), tread belt wear and need changing, motors and lower boards should be vacuumed and blown out periodically...its like the car thing again....change the oil, get new tires, periodic tune ups...
do your research before buying, and TRY the product out first. some have better shock absorbing systems, some have wider belts, automatic wax systems
******if money is no object....and from a satisfaction standpoint....go with a LifeFitness treadmill.****** They have a HUGE line of commercial, light comercial treads that are outstanding. their quality control is great....and they have strong warranties. precor is good as well, im just not a fan. too expensive to fix....constant problems, kinda fickle treads in my opinion. woodway's are great....just waaay overpriced.
also remember that if you put a commercial tread in your home....most need a dedicated 20amp circuit...otherwise it will eventually pull too much amperage and fuck up the tread....and always pop the fuse
you can also look at places like global fitness and fitness equipment source and grab a remanufactured commercial treadmill for about 1/2 of what they would cost...