We have yet to see the true potential of HT, imo, for the individual user type PC.
So, I look at it as having another trick in the bag, but certainly it is not needed. I like having the choice though. The funny thing is, some people wouldn't dream of disabling HT, even if it is limiting their raw MHz.
It is more an attitude thing I think, because once you get into hardcore stability testing, you want to achieve stability at the maximum possible load, that the cpu can be put under.
I am flexible about it, but I do have this feeling, of like looking over my shoulder, right before I disable HT, to see if anyone is watching.