Most of the original questions have been answered, so I will just post my (mostly) recent experience with Savage Worlds (SW). I followed the development in Shane Hensley's design journal at the old peginc web site. I was intirgued by his original influences and design goals. It boils down to a game that is easy enough to plan & run while retaining enough complexity & advancement potential to make it engaging to play. Sort of the best of miniatures wargaming crossed with roleplaying. The motto is keeping the game fast, furious & fun (!).
I played Deadlands and Hell on Earth, which are pretty much the precursors of this game, along with The Great Rail Wars. I incorporated chips in d20 games to reroll any d20 long ago, and it worked well. I even tried a blackjack (21) initiative system, which was not so good. I have yet to intorduce exploding dice (raises) to d20, but I'm considering it.
Anyway, a few months ago, I was really feeling burned out by d20 due to a variety of factors. I bought the revised SW book on sort of a whim at my FLGS. The cover art is much better. I read it and liked it. I figure it's about 1/10 of the pages in the PHB, DMG & MM. I have run many games in many genres, but I really wanted to try a war-time setting. So, I started shopping for Tour of Darkness (ToD).
I finally got it. I started running a ToD game last week for my weekly group. It went really well. I think it will continue. The base SW rules are great, and the ToD setting book is a good too. I likely won't use the entire plot-point camapign, but there are enough tools in ToD and on the 'net that I can present just the kind of game I want. More importantly, I can easily use the miniatures I already have on hand for the PCs, allies & foes. The best part is that I can spend more time painting and less time planning the game. There's just not as much paperwork for SW--both in & out of the game.
My biggest fear with SW is that it could kill d20 for me. I'm not sure how well SW would do for standard swords & sorcery fantasy, but I might check out Evernight next. The real test would be if I ran SW for post-apocalyptic in lieu of Omega World.
So, there's a big, personal, endorsement for Savage Worlds. I hope it goes well for you.