I have one strat with a Hotrails Bridge, I have five strats with JB's in the bridge. To my ears they sound similar in tone and output...........I would be happy with either.
The hotrail is more like an in your face type of pick up. Hot and heavy. Lots of mids. Good for Rock solo. The JB is a little bit subtle and has more highs. I mostly use it for classic rock, blues, country and jazz. They both sound good when splitted.
I've got a Strat with a Hot Rails in the neck. It's my first experience with a Hot Rails. So far I like it. It's great for rock and metal leads, not so good for rhythm work unless it's clean. It matches up really with the C5 in the bridge.