There was more conversation about drill jigs on another thread although I cant remember which one. Based on those conversations I ended up ordering the SB Xtreme.
My takeaway from those conversations was that using a jig like the SB Xtreme doesn't guarantee a perfect drill every time, but it's as good if not a little better than other methods like the original Silver Bullet or The Block. The main difference would be ease of setup and use.
Keep in mind though that I'm NOT SPEAKING FROM PERSONAL EXPERIENCE. I haven't received or used mine yet. Just passing along a condensed version of the information I got... Hope it helps, but don't go slapping down your $200 based on what I'm saying.