I can't speak for the current PC models offered, however I've had a 690 since 04, I bought the 694 kit. I wrecked the 1st motor in about 4 to 6 months, using it on composite decks, plastic melted on the windings and such and died, I was clueless. The builder I was framing for wasn't wiling to supply, replace or reimburse so I stopped taking deck frames with composite decking. I got a few bucks for the dead one, (still lots of usable parts) that went toward a new motor. The machine has seen tons of work jobsite and shop, finesse and muscle work, it gets an occasional blow out to keep it clean and that's it.
Never bite the hand that looks dirty!
The more you know the more you're worth