I think Miz could cut good face promos, and so could CM Punk, both are incredibly charismatic indeed. However, HBK just doesn't cut good promos. He's cuts incredible promos. He has to be the best guy out there to cut promos that make you feel bad about him. The mic work against JBL, Jericho and this entire year on Undertaker vouch for that, and on when heel, well, his work on Bret Hart and Canada is amazing, and we got a taste of that in 2005 against Hogan.
I want to make it clear, HBK isnt my favorite promo guy. When heel, I enjoy HHH in general more, and I find CM Punk more interesting, and in faces I like HHH more (it's sad to say that is the only face whose face mic work I really like, besides Edge in general). But when you look at it in general, HBK is amongst the best ever.