The SB is a powerful tool for sure. Vitor's is a "Boxing Blast" and I heard Bruce used it as well. Tim Tackett said there are more than a few blasts Bruce taught.
A tip to help you be more successful: It must be SET UP properly. I hear and see a lot of people trying to use the SB as an entry - that may work sometimes (anything can) but if you set it up and then "unleash" (great word!) it you'll be more effective.
Also make sure that there is constant forward pressure. If you are looping then you do not have CFP - Just as one fist clears the other should be slamming into him so that there isn't any "lag" or non-pressure.
Here's a good training tip to make sure you have CFP:
Go up to a heavy bag and extend your punch so that it moves the bag away, now begin your SB, if the bag moves towards you at any point, then you did not have CFP. Make sure your punching hand/arm/etc is driving straight into the bag, letting the hand that already hit be the one to clear the line (this assures you avoid looping).
This is just a drill obviously, since there is no footwork involved. Footwork is extremely important to transfer force and really "drive home" the CFP, still, this drill will help your upper body get the CFP down.
If you have a training partner, have him hold a focus mitt with one hand with his other hand behind it to support it. Now SB as he backs up. He should be putting pressure forward on the mit so if you do not have CFP the mitt will fall towards you and he'll feel it - he can then tell you how you did on your CFP.
As a progression, he can change tempo on his retreat (so you have to fit in) - he can also change lines, bob and weave, etc just as a real fighter may do so you can better "track" your opponent.
Just some thoughts on the SB. I love the SB as you can see
I know it's silly to say, but I love it too! Great comments/ suggestions, ta!