Yep I have a quickspool B1. I have never had a Piers HX-40 but he has a great reputation. The B1 was a little spendy but I figured I would only be buying it once. Depending on what you do with a 40 you may be buying it again.
The B1 is a big turbo but spools about as fast as my stock HX-35, not quit but surprisingly close. There is also a picture floating around the board somewhere of a side by side comparison of the two. Their is a HUGE difference. I cut my shut down time to almost non extant. I used to have to wait 4 or 5 minutes to cool down if I came off a long highway trip. Now its usually down to 330F pre turbo when I pull in the driveway (after long trip) and will cool to 290F within 20 seconds. I can shut down immediately if I have just been driving around town. I might add that I am using BD3 injector's.