I have a ASC Sunroof installed in my Aztek, was installed at the dealer when bought new. It leaks, and has caused headliner sag. If it wasn't installed by the factory, I don't recommend it. The aftermarkets drain tubes get clogged constantly. If a motor, lift actuator, or some other part of a factory unit goes bad, you can go to the junkyard, and buy the whole roof, or just the part, and you are done. Aftermarket, well, you first have to see if the sunroof company is still in business, and if they still make parts for your old unit (after 2 years, most companies stop carrying parts, to get you to buy a new one)..
Basically, I have had a aftermarket model installed in 3 of the cars I have owned throughout my driving lifetime, and all of them were a nightmare that I had to buy clear silicone, and just completely seal off. My ASC in my Aztek still works, but leaks, and has other issues. I want to seal it off completely, but my wife likes it.. GRR!