My neighbor's has have had them for a while. I do get some interference when they fire up in the morning. He has had to replace the controllers a few times, I think he's gotten to the point of having them rebuilt now to save a little. He is cleaning the panels quite often. I don't think he has had to replace any panels, but has also had to change out the batteries. The other neighbor had them installed with no batteries, had a shady kinda install that didn't set it up with the power company and disappeared.
The guys that came out and gave me an estimate priced them with no batteries as well. I don't see the point of not having no batteries, I kinda think they would be important during blackout and at night. With a 60K price tag without batteries is just a little too much, however, the sales people were a little shady as every time I asked about warranty or cleaning etc. it was all covered in the cost, for life.
I don't know if they ever pay for themselves, and constant maintenance to go along with them. They do lower the power bill though, but new regulations also don't allow the full potential for savings as I think you only get like 80% of credit, at least in my area. I don't really understand how the whole thing wotks with the power companies, but they made changes to allow the implementation to make sure they get there fair share.
I talked to a guy several years ago that was off the grid with solar and wind, all the backup etc. He told me they would never pay for themselves, and they weren't really worth all the hassle and money. When he was diagnosed with a terminal cancer he put his house back on the grid so his wife didn't have to worry about all the upkeep.
It's a personal choice I guess. Too rich for my blood.