Here's the deal Shi - B & T is a top of the line Suppressor company. That is where they made their mark and their cans are among the best in the industry.
Perhaps THE best that aren't completely customized to the firearm in question.
The TP9 Carbine that you linked isn't legal in the US without all the Federal paperwork, and even then you are paying a TON of taxes becasue it's a complete SBR.
Basically, Brugger & Thomet bought the complete design, all Rights and Patents to the TMP series "machine" pistol. Then they turned their eggheads loose and let them update and revamp some of the workings. The thing is, in doing so, they also bought all the bulk warranties that were sold with package deals on the TMP series. So, they have "outlets" all over the world, but only one in the US.
Reviews have been mixed. 9mm is still what the world wants in a sidearm, and in a lesser category, a primary assault weapon for CQB situations.
9mm just isn't that popular here in the US in primary weapon applications, and when you factor in the pricing, it's just not something that is going to catch on anytime soon.
I have been intrigued by their tactical boltgun line for about 2 years now. I want to see one up close, and see what the minds of B&T have done to improve on several known things that are inherient in the platform.
Time will tell, but I don't see B&T getting strong in the US market unless they open a facility here ( like H&K did ) to cut down on import taxes.