I haven't had a ton of time with this product yet, however it seems to work as advertised out of the box. I did have a minor issue with it only running for a couple minutes before the oil shutoff turned it off. Turns out the included bottle of oil I got had too much in it, and the level was above the operating range causing the issue. After getting that resolved it seems to run just fine.
After reviewing the user manual and looking over the inverter, this is a well designed and nicely made unit. It's even quieter than expected and not impossible to move around. Happy with this purchase.