Yes, that's exactly it. I was playing Xeen and Oblivion at the same time, and it was very clear which one had superior dungeon design. Dungeons tend to be repetitive loot/kill fests these days, you don't see the craftmanship like in the MM games.

One of my favourite parts about the games is being able to explore and experience the HoMM series in an RPG format, though that only applies to VI and VII - though those ones seem to be considered the best M&M games as well.

I love M&M VII for that. It's got one of my favourite plots in a video game - not because it's terribly compelling, but because it ties in with Heroes 3 (the game takes place between Heroes 3 and its expansion Armageddon's Blade - with your party even getting a mention in the campaign of the latter!)

There are two camps on that actually. Many players, myself included, prefer the earlier games, although I will admit that I stopped after MM6 so it's quite possible that 7 and 8 are better. 1-5 and 6-9 are quite different from one another so it comes down to personal preference... you'll see a lot of people on these forums who love 6 and 7 and a lot who pick 3 or Xeen (4-5) as their favorite.

I always liked the combination of scifi and fantasy. When I first came across the hate for it on a forum somewhere, I honestly couldn't understand it. It was like my two favorite things together in one game. What is so wrong with it? I am really sad that the new games got rid of it.

There's still some sci-fi stuff in MM6 (in fact, some specific references to the very first Might and Magic game), but I haven't played past that so I don't know about the later games.

VII as well (which, similarly, has a plot tied in to III revolving around the sci-fi stuff) but I'm guessing he meant the more recent games in the franchise published by Ubisoft. Or maybe M&M IX

Yes, I meant the ones starting with MMIX