While it’s really well made, I’ve always been thinking that making a Conan RPG based on the d20 system was a really odd and unfitting choice. The extremely steep power gradient between 1st and 20th level just doesn’t seem right. But running the Conan game in an E6 variant? Now that seems like a really interesting thought.
Conan is one of the few D20 variants that has armor as DR rules that don’t suck. I’ve never played it myself, but it still gets good reviews from people who have. Also like their rules implementation of more S&S type of magic.
You could stretch out the six levels into twelve via “half levels” that give half the HP and skill points, and either a feat or a class ability or some such.
Mongoose’s Conan is basically the only implementation of a d20 game I actually liked beyond 5th edition D&D.
You have a fair amount of prowess between 1st and 6th level, particularly compared to other humanoids.
Everyone has plenty of options for things to do (that don’t involve the answer: “Be a Wizard!” that 3.x had).
Playing a Sorcerer felt like playing a Sorcerer, and the magic system was so much better than spell slots, if a little stingy with spells. In fact, the magic system itself was what convinced me to buy into the second edition of the game. The expanded rules in Secrets of Skelos were even better.
So many combat options. Even the choice of parrying or dodging made a real difference to keep everyone invested in the game.
Between Armor-as-DR OR AC, most weapons felt like they had a reason to exist, with the notable exception of the Bardiche being hands-down the best weapon. Period.
Compared to 3.x, Less stupid feat chains and actully had feats that were interesting and useful.
It probably is a good candidate for E6, but I also feel like it would be a good candidate to convert into 5th edition D&D – I’d probably cap hit points but keep the hit die reserve, make short rests shorter and long rests longer. Keep the sorcery system. It’s the start to a dirty hack.