One of the nastalgic aspects of Master of Magic was that each race had its own units which had different abilities. Dark Elves had warlocks and nightmares (which could fly btw), dwarves had hammerhands and golems, high elves had griffen riders, and the list goes on. That's what made the game so great, was that you could see how hundreds of different unit and spell combos interacted with each other. And on top of all that, they threw in a another Plane of Existence to conquer.
As for hero balancing, Master of magic executed it well. You could get some weak and pathetic heroes that couldn't kill spiders, but by the end game you could literally mop the map with some heroes.
Elemental doesn't seem to have quite captured the spirit. Damn I wish they would have negotiated for that Master of Magic license a little harder, heh.
On a side note I am glad I kept my Master of Magic Official Strategy Guide, those suckers go for $70-140 on Amazon. lol.