And FYI
I just spoke to Mike Sanders- it was a pleasure and he in fact discouraged using the V4 with the Thiel 3.7's (which he seemed quite familiar with). The source impedance of the amp is too high and would not match with the speaker's fairly impedance dips.
This is something that unsound had been mentioning.
On the other hand he explained that the mono 120's are specifically designed for more difficult loads and should handle the Thiels well.
One of the problems of course is that this kind of information rarely readily available unless the amplifiers have been reviewed and appropriately tested.
I want to look more into this- very interesting. I just wonder what kind of output impedance would then be considered a good match- yes obviously the lower the better but that is just a relative comparison. I would like to know about the matching in more absolute terms.