I have the white interior on my nearly 2-year old P3D and absolutely love it. My previous car was a Subaru WRX with black interior. I am so happy I got the white in my Tesla. It makes the interior feel light and bright and even bigger. By comparison, the black interior of my previous car felt heavy and, at times, a bit depressing.
My white seats look just as good as the day I took delivery. To keep them looking white, you do need to do a bit of upkeep. I wipe them down once every week or two with a general purpose interior cleaner. And if I notice a stain from my kids or my dog, I tend to it right away.
The worst stain I had was from a valet. He must have had a blue thick marker in his back pocket because when I got home, I noticed a large blue marker ink stain on my driver's seat. I used a strong APC and it came right out.
BTW, the glare issue, IMO, is only a major issue if you have your front side windows tinted very dark. I have my windows tinted with a light 55% tint and have no issues at all.