We've had the Champion 2000 for about 3 years now.
When I bought it, I never expected it to run my air conditioner so I haven't even tried. But we've never had a problem with it and it powers the camper and charges the batteries just fine. It is pretty quiet, although it burps sometimes when it runs. We bought ours new, not reconditioned but I think the reconditioned ones carry the same warranty. We even took it out west and it ran pretty well at mid-range (circa 8,000 ft) elevations.
I would have no hesitation in buying another one if I needed it, but now that they've developed more products, I'd probably buy the 3000 model. It has a good price for what you get.