I have a pair of the same inverters and I keep my fingers crossed. However, I also bought a set of internals about 7 years ago and they sit in my spare parts drawer.
My inverters weak spot is the relays, and fortunately if they puke I can get replacements. They are just 30 amp, 120V relays so even if I cannot get a direct drop in replacement I can still do a repair.
I am so anal about them they have a ductwork going into them and I run a pair of fans to keep air moving through them whenever we are using the coach. That is in addition to their internal fans which are thermostatically controlled. In addition every few years I open them up and vacuum and blow any dust from them. So far, so good.