On the whole, I think the new sandblasting process has produced noticeably better results than recent vintage Peterson sandblasted pipes. The grading is good business. I own a few of the SP 20th Anniversary pipes and I think the blasts themselves are quite good. I think what they've achieved is deeper blasts that show interesting patterns in the grain. What they lack, when compared to my favorite deep blasts, is excellent sharpness and detail. Then again, they're a fraction of the price of a JT Cooke or Michael Parks pipe. I think these new Petes are an outstanding value.
Holding the newer Peterson sandblasted pipes in my hand (specifically the SmokingPipes 20th Anniversary Pipes), they feel like they've been sandblasted and then either sanded to remove any sharpness or coated with a thin paint. I doubt that either is actually the case. More likely, it results from a combination of Peterson's process, blast media and briar. The pure black finish on the SP 20th Anniversary pipes looks just a little cheap to me.
I have an older Peterson spigot billiard from probably the 1980s which has significantly better detail and sharpness which is accentuated beautifully by a bright burgundy understain. I like that the new PSB grade pipes have a red understain, as it accentuates the blast and provides a rich look overall.
Looking at a JT Cooke blast, there's not only the extremely deep blasts, but also feathery details of the grain. That sort of blast isn't appropriate for every pipe, but it's sure gorgeous when used appropriately.
Here are all three that I mentioned above. From bottom left to upper right: 1980s Peterson, Peterson Smokingpipes 20th Anniversary, and JT Cooke.