It occurs to me that you guys probably wouldn't be able to pinpoint any changes since you're not standing next to me when I brew.
That said, I suppose it could be a combination of things that have all had a positive impact on my beers overall including the head. The part about the shorter boil time is very interesting to me and I mentioned that over on my main board too... with so many homebrewing myths I usually wonder about changing something in my process because I'm afraid it might detract from my beer. In the case of boiling for a shorter time, it's possible that there may actually be a benefit and I didn't even think about that. I've been brewing since 1999 and I have heard many myths and people like Marshall (Brulosophy) and others have done some great work to debunk things over the past few years. Cheers.
EDIT: Denny, the other thing I'm seeing is that the BTB seems to really have some impact on clarity which I understand is one of its benefits. You know I'm a clear beer freak but between the 'smoother, softer' beer, the better head formation and the clarity, I'm a very happy brewer lately.