Just a personal story from my own experience, but I'm sure that there will be a few "nay-sayers".
TMI - "True Stories"...lol....A few years ago, I lived in New York, Which is really not what you call a Hot state..Maybe 2 months out of the year..if that.
I had installed a set of New TMI upholstery on a daily driver '66 that I had. Installation came out great as I have been doing professional unholstery for 20 years. I literally drove the tar out of the car on a daily basis back and forth to work about 20 miles a day for a two year period. The Driver's side seat literally "cracked" on one of the top side bolsters, and on right side on the seat bottom. The stitching literally separated on the left side seat piping bottom. This all happened within a two year period. I am not a heavy guy, about 176 pounds..which is average. I was shocked at the damage all unfolding before my eyes..so after only two years, It was time to replace all over again. A buddy of mine who was a Mustang Parts Distributor actually carried both brands and let me open a few boxes of TMI and a few boxes of Distinctive. At the time, I was finally able to compare the two side by side...and the difference became quite clear. The TMI vinyl fabric was actually thinner, and had thinner padding. I held it up to the light, and I could actually see light coming through the stitchings. That's never good in any case. Then came the Distinctive test. I did the same thing. The Distinctive had thicker vinyl, thicker padding, even heavier stitching!! I was literally shocked at the major differences. Now TMI does have some advantages...but not in the wear characteristics area. That is for sure. TMI has more correct piping, and crisper, more correct patterns as in the case of the Pony interior. As I said up above, The choice is always yours. You have to know what you want. Take the test yourself. Order both interior brands, Compare both, then return the one that you don't want. What will it cost you? Shipping? All I can say is that I am glad that we have both brands to choose from. I've told this story before over the years, and here it is again..so decide for yourself. Don't take my word for it.
I was a Distinctive customer after that.. I was sold. Never had an issue again.
I would still use TMI on a show car though..One that does not see daily use as it is "more correct".
I don't know if TMI has improved since then... It's possible that they may have but I don't know.. I still love their door panels though!