Sound — 10
This pickup is pretty badass for heavy stuff. The clean tone is also beautiful if you have clean playing. I understand this pickup isn't for everyone, but it most definitely has a place in hard rock and metal. I'm currently using an ESP ltd deluxe (EMGs) through a Blackstar ht metal 100 and the sound is colossal!! They aren't as versatile as some passives but they are really good at what they do. Haven't had any problems with excess noise. If your not used to actives I recommend giving your ears at least a week of playing to adjust. Experiment with amp settings... etc and you will dial in a badass heavy sound in no time!
You can listen to some of my sound clips using this pickup here (use headphones or good speakers for a better listen):
Reliability & Durability — 10
The pickups are cased so unless you really do some crazy stage antics and throw your guitar or drop something heavy on it, they should last forever. Don't pull a kurt cobain and smash your guitar, unless your either quitting music, which never happens, or your already a rockstar and you can afford endless amounts of new musical equipment. They are actives so make sure to keep an ear out for the signal. If you notice the sound starting to thin out you probably have to switch out the battery. Haven't tried the 18 v mod yet, heard great things.
Overall Impression — 10
I play basically all kinds of rock,classical, blues, jazz, flamenco, everything really. But my favorite and specialty is heavy rock and metal, some shred here and there. EMGs are definitely a good fit for the heavy stuff. I've been playing for 16 years now with tons of experience with gear of all sorts. I own a bunch of EMGs, Seymour Duncans, DiMarzios, Gibsons... and so on. EMGs definitely hold their own. If lost I would probably buy another set. Overall the EMG 81 is a really solid and awesome hard rock/metal pickup. Sounds great in the bridge. Rock on!