Some information and facts:
1. The mid range driver in the bigger models is not from ATC. It was in the past but PMC took the design, improved it, now they build it in house.
2. The best bang for the buck is the IB2i. You get almost the sound from the big monitors without the huge case. For more bass, get a sub woofer.
3. It's often claimed that a TL design is easy to engineer and compute (there are programs that give you details). I talked to PMC directly. The new FACT for example took two years of building, testing, listening. It's a combination of the housing, drivers, dampening etc.
I think PMC's are one of the best all-around speakers. However, the fun really starts with the big speakers. And these LOVE powerful amps.
I can listen to them for 8 hours without getting worn out.