Re: Surfers v.s. SSL-1
First, you've got to ask yourself if you're even a vintage strat sound type of player.
If you hate the sound of stock strat pickups, you won't like either, and should go for something that suits your musical style.
If you DO love the vintage strat sound, and your ears can tell the difference between the different high end strat pickups, you'll know that the Surfers have a bit more complexity, depth, and sweetness to their sound, compared to SSL-1's. What you're paying for is period correct materials, which are made by a veteran, not an hourly employee. They come in a better package as well, which cost Duncan more money in presentation......complete with filter dust that simulates what a set of old pickups sitting in a 63 strat might look like over the course of 40 years.
The simple answer is that they sound slightly better.....enough to justify the difference in price, to a discriminating ear.