It arrived with a little shipping damage and MaxTool sent a replacement air box right away, two bolts and it was fixed. I've been breaking it in for the past 10 hours or so with varying loads and it hasn't skipped a beat.
I expect to be using it regularly in the fall because of our local power provider doing planned power outages for fire safety (PG&E) it'll get tested well then.
I only have one concern, I hear a intermittent pinging or minor engine rattle, especially when it's not under load. My wife doesn't hear it, my neighbor doesn't hear it, but I'm an ASE certified auto technician so I'm probably especially sensitive to engine noises. It sounds like valve clearance too loose but it's not in the top end when I listen with a stethoscope; it's in the bottom end or the armature/generator portion. Maybe it's nothing, like when you're riding a motorcycle and the clutch/drivetrain makes all sorts of racket that is totally normal but sounds funky.....I hope that's the case. I'll update this review in a year and let you know. If everyone else could hear this noise I'd be more concerned, but I'm all alone.