I have had a Sfiligoi fixture over my tank for around 4 years. Started with a 12 bulb Stealth T5 fixture and that thing was a beast and worked beautifully until I sold it to a friend (who is using it and loves it). I sold it due to an upgrade. Upgraded to an XR6. It is just an incredible fixture. No issues at all.
I'm sure you can find at least one person who has an issue with just about every type of fixture out there (TEK, ATI, Marineland, LED stuff, Sfiligoi, etc). No lights are perfect and as long as there are wires, bulbs, and electronics, there will ALWAYS be a situation that isn't perfect. While I have not run into that, I know that if something were to go wrong, I could pick up the phone and talk to Tim @ Aquatics Elite. He would take care of any issues that came up. Can anyone tell me the number to ATI Customer Service? How about TEK?
Service after the sale is KEY when you're spending $$$$ on a fixture. Tim has spent countless hours with me helping me program my Apex correctly for my light. That's not his job, he doesn't get paid to do it, and he gains nothing from the help. But he takes the time to do it and that is just a small example of things he does to help out those who buy from him. The build quality cannot be beat on the Sfiligoi's. You get what you pay for. While they are expensive, I have never (personally) heard one person ever complain. You don't have to own a Sfiligoi to have a successful tank by any means. I also have an ATI PM over my frag tank. It's a nice fixture as well but it lacks some of the features that a Sfiligoi has.
If you have any questions about either of the fixtures that I've owned, feel free to pm me anytime. Hope this helps a bit.