I've heard different opinions about TPs taste. I would like to try it first. Such a cool mango itd be awesome to have it even just as a collectors piece. I also try to buy locally and I don’t believe the growers I know carry it. Sounds like you're convinced on it. Are you growing it as well?
I went to Xain's with a buddy of mine and we were chatting with Xain and his brother. We tried a bunch of fruit, including a Thai Purple mango which really stood out with strong sweetness, classic mango flavor, nice texture all from a big size mango fruit. I'm out of space in my yard but my friend immediately bought a tree. I am pretty tough in my evaluations and I give Thai Purple a strong passing grade for those with the space to grow it. If you are looking to grow a big fruit type of mango like Harvest Moon or Valencia Pride, I would go with Thai Purple instead.
I didn't take a photo but it does appear in the top left corner of Xain's mango poster. It's the big old purple one:
