I have the Seymour Duncan but I've never used it, it came with my SD MM replacement pickup.
I have the SGD 2 band pre currently installed in my SR4. It's set up as the high gain option that he does, and I have no complaints on the hardware. It's a very nice pre, but based on current threads and dealings with SGD I couldn't recommend it.
If I were to get new preamp I'd probably look at the Nordstrand or the East as they seem to have what I like in a MM preamp.
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