I hear you about the Textar pads, Emil. I researched this back in 2008 when the car first was released in Canada, and you could buy these pads from BMW Canada but they were literally the Euro price converted to C$ and doubled. I kept looking for other pads.
The reason I made the Pagid connection was something that the Pagid Racing distributor in Florida said to me on the phone about BMW Motorsport liking the RS19's a lot. Back when the car was first released here, and I'm talking April 2008, there were NO performance brake parts available from anyone with the peculiar exception of the BMW Sport Pads and Pagid RS19's. If you then go over the list of BMW's that share the OEM front and rear pad outlines with the E9x M3, you discover that while the rears are shared with the M5/M6, the fronts are shared with regular 5-series cars. It didn't seem likely that Pagid would make an endurance racing pad like the RS19 for the regular 5-series. And besides, neither BMW nor Pagid listed a racing/sport pad for the 5's, so that was the end of that trail.
So those are the dots I connected, but that's all the evidence I have. That said, Pagid and Textar are both operating subsidiaries of TMD Friction. If I were Textar and my core competence was making high volume OEM ("non-performance") brake pads, I'd source a low volume specialty pad like the BMW Sport pad from a sister company that makes racing pads, and that would be Pagid. My RS19's squealed on the M3 and worked really well on the track.
As an aside, I liked RS19's so much on the BMW that I'm running them on my 2011 Mustang GT with Brembo brakes, and they work just as well, wear very slowly and don't squeal.