Well, I have heard it myself now.... exchanged it for my SDAi2175 last weekend and had it at home for week, and tried it without using any of the EQ capability fed direct from my transport.
To cut a short story even shorter.... I couldn't wait to get the SDAi2175 back, and amazingly for about the first time ever I agree with WM about something - the TacT TDA robbed the life out of the music and made everrything sound dull. Fantastic texture - especially with modern classical music with interesting percussion, but lacking forward drive and momentum, so not fun at all with most music.
Anyway, I reckon it might be the interaction with my speakers, the ATC SCM12, which are not the most forward sounding things nor very neutral, I like their holistic big picture rendition... The SDAi2175 may balance very nicely with this, but the TDA2200 might be better with a very upfront or neutral speaker. But I won't be trying it again.
The relief when I got the SDAi2175 connected back in yesterday was considerable.