So how many KW are you looking for?
I've heard of quite a few people who've had issues with Generac....a lot of it had to do with difficulty of sourcing parts, boards, etc, and certain parts being obsoleted quickly. I just brought back a Generac unit to life that came into a scrapyard -- not that old, but used an offshored diesel which was hard to find parts for. I got the impression during my parts search that Generac used an "engine of the month" back then, just putting whatever engine they could buy cheapest into their units. That was a bigger generator, 125KW, and I don't know if the smaller ones have more or less of an issue with this same thing. They had even cut the I.D. tags off of the injection pump, etc to make the engine nearly impossible to identify and order parts for on the secondary market.