I am a HUGE fan of Audyssey, Audyssey Pro and the Audyssey SubEQ. Given that you can purchase an $800 reciever and get that kind of functionality is absolutely amazing to me. And for HT, a pre-pro with Audyssey and Audyssey Pro is an outstanding solution. You can purchase used for under $1000 any number of pre-pros that support Audyssey Pro and that will provide an incredible HT experience. To get better, you really need to spend a LOT more. That is what I use for HT.
Having now played with both the Tact and Audyssey, this is my opinion:
For two channel listening, it is no contest as I believe the TacT is a FAR better solution. But remember that the Tact cost up to $6800. It has FAR more flexibility in terms of Target curve definition, crossover settings, instantaneous listening of any small change you make to a target curve (unlike Audyssey Pro where you listen, re-load all of the filters and then listen), filter resolution, etc. And while it is primarily a single point correction, according to Boz, it can learn about the room in those single point measurements and "simulate" other room postion correction parameters. The older Tact that I also have does provide the ability to measure up to 9 positions but, according to Boz, that is not necessary (I don't actually buy that given my experience with the Audyssey SubEQ). Net net is that in my opinion, you will get a much, much better two channel listening experience with the Tact than with any combination of Audyssey supported products --- with one possible exception.
Even though my pre-pro supports Audyssey Pro, I purchased the Audyssey SubEQ. It (in my room) greatly improved the bass frequency ringing that Audyssey Pro partially dealt with. I have a dedicated room and is very heavily trapped. The HT bass with the SubEQ is outstanding. When I get some time, I may try the SubEQ with my Tact for two channel.
If I were to purchase what I believe to be the outstanding combined solution for HT and two channel (the best -- who knows?), I would purchase the TacT TCS system and probably the Audyssey SubEQ. That would be a dynamite combination in my opinion.