How would you compare the Master Blast using say...EMG 81's as a benchmark?
Say what? Totally different. Nothing like each other. Actives sound sterile. I can say that, apparently Im the highest selling authorised dealer of EMG's in Australia. I hate them.
Great for down tuned and baritone guitars. But I hate them for anything else.
The thing to keep in mind is you want the pickup to provide more than just gain to your amp; you want it to have tone and character and then let your amp do the work. A 'hot' pickup is really only good if you use a non-master volume amp and need to make the front end go nuts. Seeing as hardly any 'metal' guys use non-master volume Plexi's or the like, you're much better going for something that's not as hot and provides a cleaner, more balanced signal to your amp, that will allow you to utilise your amp's tonal palette alot more.
Leon has nailed it. Guys who have tried the Nunchucker, are giving me fantastic feedback. However, it isnt what would be classed as a high output pickup. You dont need a high output pickup these days with modern amplifiers. You gotta remember, the entire aftermarket pickup industry started because people couldnt get gain from their amps. So they blasted the front end with a Super Distortion, etc. But, these days you can just turn a gain knob on your amp. Why blast it with something that is too hot, effectively loosing guitar tone, but adding a hot sterile signal?
Go plug into a Plexi/Metal face Marshall. Go try a JCM 800. Then plug into a Mesa Dual Rec/5150/ENGL/DSL/Whatever. You can see the JCM, Plexi, etc need a bit of a helping hand somethimes. The Mesa/5150/DSL doesnt.
There are sooo many people, even on this forum, that I see talking about buying these monster high gain amps, then using only the clean channel, and a high output pickup, through a distortion box of some sort. I think thats the wrong way to go.
Guitar. Pickup. Amp. Forget the rest of the crap, go back to basics. Let the guitar provide the initial tone. Let the pickup SHAPE it. Let the amplifier gain it up. Less can be sooooo much more.