I 've got experience with both HD and MM in superstrats. I would say that both had a lot in common but the HD is more versatile, more classic (though being modern), is the pickup for all these hard rockers in the 80s that had not enough with their current pickups and the HD is that step towards "modernity". You can cover from fat blues to metal. But for me then came the Miracle Man, for all these that said "ok, great pickup, but I need even more!". Of course MM is named after Zakk Wylde, but for me is the pickup to get closer to George Lynch tones. For me George Lynch was the heaviest guitarist of the 80s but was imprisoned in the hair metal movement. You can get close to his tone with the HD, but my experience is that the extra heaviness and aggression, this feeling of being on the verge of feedback, is easier to get with the MM. Of course you will lose versatility with the MM.
I have a fender strat with HD bridge and Irisht tour in middle and neck, and is my allrounder guitar. I can play almost everything. But then I have an Ibanez rg with a MM and is the perfect combination for this "heavier side of the 80s and beyond". And I don't mean only Metallica, Slayer, Pantera,... but, as I said before, this "Lynch-esque" kind of sound that had a lot in common with the HD, still thick but slimmer and edgier.