My point was not to pick on HT subs but to say that a single HT sub integrated into a two channel system can impose additional problems if placement is less than ideal.
When using two subs in stereo there is more flexibility for tweaking each sub for its placement crossover and slope without allot of additional EQ. But then again the room size will need to be considered for the particular subs.
I've heard quite a few different HT subs in a two channel set up and they tend to be over equalized for two channel but do a great job in HT.
I just have not heard a HT sub go from HT to two channel seamlessly. Two channel bass is more challenging to harness than HT.