Thinking about the last post, I'm wondering if folks have a preference for which rules support different styles of play better or worse? Standard versions of D&D do fine in the High Fantasy and Swords & Sorcery space. D&D and the clones are fairly high powered and need some surgery to work in the low magic space - those green 2E historical books always had a healthy chunk of things to cut out to make the game more grounded.
Regarding the new games, DCC RPG looks to live in that Swords & Sorcery place, with the wizard pacts and moral ambiguities that come across in the rules. I can't see Gandalf slashing his arm to spill blood to Blodbu… - whatever the frog god thingie is in DCC - to empower one of his spells, despite how awesome it would be. (Although as an angelic Maiar, maybe his patron would be a being of light - what do I know?)
LOTFP goes after the low magic style, with grittier combat and toned down spell lists. Note that both games ditch the 9 point alignment scale to work with Alignment as Allegiance and not Alignment as Ethics, further getting away from the good vs evil vibe of standard D&D.
As a DM, I choose low magic more often because I can model more elements from the real world (ie, general DM laziness) without needing to project the massive changes to society that would come about due to Raise Dead, common magical healing, Plant Growth for mega crops, Continual Light, and all the other reality-bending things we can't even predict.
Players, on the other hand, want Swords & Sorcery. They'd prefer loose alignments (if any) to maximize freedom of choice, tons of race and class options, and more powerful options all around. Just generalizing, mind you - your players might be different.
Just an aside - does anyone know of a setting or treatise that take magic to it's logical conclusions in a D&D setting? The closest ones I can think of were in the Known World Gazetteers - Glantri and the Empire of Alphatia. Both were ruled by wizards, had magical construction on a wide scale, flying ships, changes to agriculture and the social structures due to magic, etc. But the Known World (Mystara) also postulated meddlesome gods (immortals) that kept the world in line and reacted if any group got too powerful. I never read Eberon, but I I know it featured quite a bit of magic-as-technology.