With all the new 8 strings on the market you can reasonably most of them are being used for metal. Before EMG started making pickups for 8 strings no one really knew how good an 8 string was supposed to sound. People were making 8 string pickups like normal 6 string pickups and they ended up being muddy with all the extra low end. The EMG 808 was one of the first pickups designed for 8 string guitars. The extra bite the active pickups provide is perfect for keeping the low strings tight on an 8 string. Some people dont like the sound the EMG 808s put out. The sound they put out kinda sounds like you have an extra sizzle on top of your real guitar sound. This extra high end sizzle is what keeps the sound so tight on the low strings. Without this extra high end it may end up sounding more like a bass guitar than a guitar guitar. These pickups are very sensitive to setup. Your sound can easily be adjusted by raising or lowering the pickups. If you are running EMG 808s I recommend the 18v mod. When you double the battery power you get a boost in output and it makes the sound that much richer and more organic. Some people do the 18v mod to make their EMGs sound more like passive pickups. There is a reason why most 8 string guitars come with these pickups installed from the factory. Companies dont want to spend the time and money desigining their own 8 string pickups when the perfect one is already out there. EMG also has a variant called the 808x which is designed to have a more organic sound to it from the factory but still remain even tighter in the low end. The EMG 808 is the standard when it comes to 8 string pickups.
I picked up a pair of these mics on a Ibanez RGA 8, about a week ago.
The only other pickups 8 strings I've tried were those in place in RGA8, which were particularly bad.
The big highlight is the accuracy, integrity and dynamic microphones. Balanced on 8 strings with a low in the low mids more pronounced than EMG 81 with six strings. It's a bit analytical and almost cold, as might be expected. In bridge he put forward the very attack, aggressive distortion and flapping in the clear. In the neck position, the microphone is more round, without ever being greasy. U.S. sounds very, cold. I was looking for a sound close to the EMG 81 but for 8 strings. I'm not disappointed, even if the record is not the same (with the edge 808) is the same philosophy.
90 euros for the microphones, I find it very correct. Sold complete with electronics and wiring system even easier than they could sell about 5 years ago ... almost no welds to do, everything is plugged or screwed in dominoes. Very seriously.
I would do that choice yet. That said, I'd love to hear 808x or blackouts, some say good things on forums.