I think they sound exactly like a brand new pickup in a brand new strat from the 60's.
That's the way they sounded, clean with low power output. In all honesty nothing special, it really took time for them to break in and start sounding good. Some of the fret work was horrendous.
That's way Clapton's strat was a partscaster, he took a number of guitars until he found the right mix of pickups, bodies and necks, then made Blackie.
http://doodlesite.com/crowdie/ec/blackie.htm
Our idea of what a 50's and 60's strat sounds like has been changed. Mostly because of Hendrix, Clapton, SRV and other strat users who either modified their guitars, amps or used pedals.
But as I remember circa 1968 a brand new strat through a brand new bandmaster sounded like a clean machine even when turned up. Actually not very good at all.
If you want a strat to sound more like an aged/abused one the way to go is the Antiquity series. Clean, go for the surfers, dirty, the Texas Hots.
I have both and they sound great. The bridge is very hot and I miss the quack in the 4 position so I had MJ wind me a tapped version at 6.5K. I use a super switch and the 4 hole is the middle and tapped bridge. Works great and sounds the way we think a strat should sound. I'm sure after about 5-10 years those SSL pickups will start sounding better, the antiquities are hotter than stock strat pups and that helps. But they are aged by Mr. Duncan. Most winders do something to their strat pickups to make them sound better.