Where will it be parked outdoors? My driveway has trees over it, and the dirt and debris that rains down over time would eventually clog the drains. I'd know when they were clogged because my truck would be full of water. It was a huge pain in the butt that occurred once a year or so.
If you park under trees, make a note to clean the drain plugs periodically. If you do that you may never have a problem. If you don't, they will let you know when they are clogged by depositing lots of rain inside your truck.
The other problem I had was repair costs. When the much smaller sun roof broke on my last truck they wanted $2,000 to fix it. Most of that was labor. If you keep the truck a long time, consider the cost of breakage. At the time mine broke, the blue book on the truck was $20,000. That meant I'd need to spend 10% of the value of the truck to fix something I hardly ever used.
I park outside too, and I never want another sunroof in my life.