I bought it basically without testing it, I just checked few demos that compared it to some other high gain pickups, I wanted something that had a little bit more bite in higher frequencies and relatively tight low end. It is decently priced, of course you are not getting a level of clarity and quality you can get from more expensive pickups like Fishman Fluence but if you are on a budget and want a high gain/output pickup that will get you great tone for metal, with enough clarity in top end a tightness in low end to chug some heavy metal, shred until your fingers bleed, burn a church in your village with your new black metal riffs or even prog a little and don't want to waste a lot of money - get this pickup.
This one is of course a trembucker, it has a different width and position of poles for use in bridge position in a guitar with tremolo system like floyd rose, if your guitar doesn't have one then you should get a regular humbucker version of this pickup)