They don't have much of a crunchy sound for being EMGs in a supposedly Metal Guitar.
I'll take HZs over Duncan Designs, V7s / V8s, or any other mid-range guitar pickup. They're not EMG actives, but they definitely hold their own and get the job done. Of course I'd take a Seymour Duncan JB over an a HZ (I'm not fond of actives). But if you're buying a Jackson with a JB (or EMG actives) in it, expect to pay 30% more for the axe.
Like I said, compare those HZs to Duncan Designs and V7/V8 (notably in Ibanez RG series) and you'll be blown away by the difference.