I'd be very interested to hear how you get on Horsehead - I'm only a week ahead of you on this BKP thing.
I wasn't on the forum but I was deliberating ITs for ages. A few months back I nearly switched to Mother's Milk after hearing the same clips. But I decided to stick with my original plan.
I'm still not sure I made exactly the right decision - BUT I love the sound of the ITs (and the replaced Texas Specials in an old Squier have brought that to life as well).
It's taken me nearly a week now to get the IT heights sorted to my satisfaction, but with each day I'm more impressed with these pickups. And I haven't even put new strings on yet!
And I can confirm what Tellboy says - now I've started with BKPs, I want them on everything. I'm already planning my next set, and I even find myself looking for new guitars to put pickups on...