I might be a little off on the description of the SE, but i think this is generally what I had read.
The SV's are supposed to be as close to a traditional single coil sound as carey could get from a split coil design. I think that growly and rough are usually used.
The SE's are i think what you'de expect from this design (with all that wonderful nordstrand goodness of course). Slightly more low mids, and possibly lows.
Check SMASH's review of them. (it's stickied at the top of the page)
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"J" pickups discussion and comparisons. )
It pretty much sumarizes everything that I could find about them (I went with the SE's though... my pickup is too close to the bridge and I get tonnes of highs out of it anyway) It sounds glorious though (in a PJ with a nordstrand P)