Or, XW Pro is a grid-tie inverter and California (we lead/drive the nation, you know
) now has as law that grid-tie systems installed by a contractor must come with a 10-year warranty. Along with an estimate of power produced, what it will save you, and a hand-written statement from the homeowner saying why the system is in his best interest. (made the last one up, or rather paraphrased it from the requirements to obtain a refinance.)
Me? I don't like warranties. I like reliability.
So the real question is what the track record and failure rate are for XW Pro, Magnum, Sunny Island, Outback ...
I have some data on grid-tie Sunny Boy SWR 2500U. I've had 5 of them for about 15 years. Two died, one in warranty and was repaired for free. I saw a blown up trace on a PC board, which they replaced. The other had a power transistor that blew a crater. It was out of warranty and I rearranged the panels onto remaining inverters, never got around to attempting repair. Have since bought more of later models new and used, to work with battery backup.