From the manufacturer:
Some players find the traditional Strat® bridge pickup sound clear and sparkling, while others think it’s almost painfully bright. You know who you are, and the FS-1™ is for you. It’s louder (about 25% more power) than a stock single-coil, and smoother and fatter-sounding all-round. When you combine the FS-1™ in the bridge with True Velvet™ in the middle and neck, you’ll have a guitar with calibrated, balanced tone in all five switch positions. For a bigger, more aggressive sound by and large, you can also install FS-1™ pickups in all three positions.
We didn't design the FS-1™ with a vintage sound in mind, but if you're trying to get a blues sound from the bridge position of a maple-neck Strat®, you'll be very happy with the extra mids and bass, and the sound still cleans up when the volume is rolled down.