I don't like the DR changes especially. Sorry, that +5 Holy Fiend Bane (evil outsider) sword can't bypass the demon's defenses. So stupid. Who the heck asked for that change?
I would have rather seen a different change to Haste. If the extra spell from haste makes quicken spell unattractive, then the same logic should be applied to the extra attack making 2 weapon fighting not worth it, etc. If they don't change Quicken Spell to make it better, then spellcasters are going to have a hard time. I don't see backwards compatibility as problem, since the new haste is just as imcompatibible. Every high level adventure I've seen has the casters using haste to dump spells faster. Instead of changing some stats, the entire tactics and encounter balance would need to be redone. Also, the haste change hurts fighters too, since they could no longer partial charge+full attack.