I've read the AR1 as far as the Spells section, and here are my observations/suggestions/comments:
Races: Small changes overall, but just enough to give the races a little "Pathfinder" flavor.
Classes: Excellent customization work, especially for the Rogue and the Fighter. I like the idea of the Wizard's Arcand Bond instead of the Familiar, as the apparent removal of the spellbook's page limit. When Paizo talked about streamlining 3.5, that's the kind of solution I was thinking about.
Skills: The new Skills list is far more "intuitive" this way! As for the removal of the Skill Points system, I'm not sure yet, although it does streamline the rules (you either have the skill or you don't).
Feats: Nice changes, but Feats being what they are, there seems to always be room for flocks or them… ;)
Combat: By far the best changes I've seen! The whole CMB concept is cunning, dead-on easy to use and brings a sense of dynamism that's perfect for fast-paced combat scenes. Turning is now grittier, meaniner… and better! Now THAT's what I call Turning Damage! As for the healing stuff, I'm not sure either for now, but the possibility of healing foes at the same time as your allies could bring some dramatic roleplaying scenes (should the Cleric turn the evil Sorcerer's undead troops, even if it also helps his living lieutenants?).
Spells: Haven't read this section yet, but from what I've seen with the Domain lists, the granted abilities/powers look great (and may alleviate, in my eyes, the fact that Cleric and the Wizard seem to be able to cast less spells now).
Suggestions:
• Hit Points: The tie between Base Attack Bonus and Hit Dice is clever. In my campaign, I use average, fixed HPs per level (maximum HP at 1st) and it could work the same way now with some customization possible (e.g.: racial and class bonus).
• Dying: You shouldn't fall unconscious automatically below 0 HP. This variant rule by Jester King (link) could be a nice change to do (I'm actually using it in my campaign).
• Shield Use: When I was young, I played an RPG called Lands of Legend in which the shield was used in a dynamic fashion (when you were hit, you rolled a dice and if you got a 1, you've blocked the attack with the shield). I've always felt the idea that the shield was only a mere variable in the AC sucked and veered people away from using them. When I'll get the chance, I'll post the rule I've come up with for my campaign about dynamic shield use.
Questions:
• XP: It seems you have streamlined the XP rules, but do you think it could be better if we had a XP calculation like the old times (no more messy arithmetics involved)? :)
• Character Sheets: Will you offer Character Sheets (in PDF format) reflecting the changes made in AR1?
That's it for now… I'll read the remaining chapters, put those new rules to work and write a new thread about it!