Prof - thank you for your appreciation. The "live with" factor was an integral part of our designs.
Jay - there are two periods of post Jim Thiel designs: the x.7s including the 2.7 and 1.7 and the MCS?.7 prototype. The physical CS2.7 was principally developed in-house by Kathy Gornik, Rob Gillum and Dawn Cloyd in tribute to Jim's practice of incorporating series 3 breakthroughs into the series 2 at lower cost. Part of that cost savings results from minimizing amortization of development costs of series 3 technologies when applied to the series 2. The 2s have always been bargains.
The electrical engineering was done principally by a Canadian consulting engineering company using the Canadian Research Council anechoic chamber and design facilities. I have been told but do not remember the name of that company. A few outside opinions were also solicited, but did not generate material contributions. Serious $6 figures were consumed developing the 2.7, leading to the need to sell the company. The twos had generally been somewhat "easy" since they benefited from the generosity of the threes.
After the sale things happened fast, but of material consequence is that Bob Brown of Boston-area upper mid-fi experience was brought in as consulting operations manager who brought in Steve DeFuria, a long-time Thiel retailer, knowledgeable insider and sales executive with various Boston-area upper mid-fi brands. Bob and Steve hired Mark Mason formerly of PSB and freelance designer for SVS. Mark determined that Jim's phase-time coherence was not important enough to merit the significant difficulties it caused. The new owners wanted to exploit the name and chose to pursue mass-market Chinese-made products.
The 3rd Avenue Series (TT1, etc.) were developed by Mark Mason with help from New Thiel's considerable in-house engineering chops led by Dennis Crosson. The products are commendable for a new market entrant; but the marketplace was flooded with very good ordinary speakers. They spent upwards of $10million doing the dance that many of us witnessed with sadness and chagrin.
Additional factors tied the hands of the new owners, but those remain behind the curtain until answers might come to light. Jim's copious lab documentation is nowhere to be found.
Thanks for asking.