I installed this pickup in the bridge of an old guitar with useless pickups I had lying around. Since the pickup comes with all wiring and pots, battery clip and output jack, this is the only new "component" I had to buy. It brought that guitar back to life, it went from almost no output to a nice high output when the volume is maxed out.
It's great to play some harder rock and metal and if you tweak your amp and volume you can even get some useable clean tones out of it, alltough that's probably not why you would buy this pickup.
There are loads of well known guitarists using EMG 81's in their bridge position, the 81 is often paired with the 85 or the 60 in the neck to give more versatility to your guitar.
I'd definitely recommend this pickup, It's easy to install, great for heavier music and not that expensive if you think about it (wiring, pots, etc included).