Re: new pup for a les paul jr...
I own both a Les Paul Junior and the Vintage Soapbar Bridge. First off, the stock pickup in the Junior is very nice. It's basically your classic p-90. Very articulate. It provides great rock crunch and is very balanced. It can do really nice, full clean sounds. I find that the balance lends to an almost piano-like quality to clean sounds. The Vintage Soapbar is basically more of the same thing. It is a touch hotter with more raw and gutsy midrange than the stock Gibson, but not much different. It's a tad more compressed and not quite as open. It uses an alnico 5, just like the stock Gibson. The antiquity uses an alnico 2, and (although I haven't tried one) it's supposed to have a softer attack, less high end definition, but a sweeter, more complex tone.