Well, honestly, I am perfectly fine with the superfast-healing PCs. It is not much fun to see a low-level campagn come to a grinding halt every time I throw a bruiser at the party. People often complain about the 15` Adventurer Day, but in game systems where wounds take long(er) to heal they are pretty muchg the norm.
And on a second note, in a vancanian spell system slow healing really is a punch in the face of the wizard`s meatshields..ermh, I mean his trusted companions. So, I can beat this ogre with my axe, take 14 damage, rest a week or cast "sleep" and slit his throat? Waaaaaait, which option is preferable whenh it takes only 8 hours to regain my spell, tell me...
The goal of the vancanian system the way Monte Cook puts it for DnDNext is to limit caster potential, not to set their surpremacy in stone.
And it always felt a little awkward to go shopping after kicking your first 3-4 goblins`butts to get a Wand of CLW. Or smuggle it into the 'entirely random` loot list as a DM.
It is not logical to heal from quasi-dead to Avatar of Live after a good nights rest and it may hurt immersion a little but it is a lot better than have the party retreat after every encounter.
D&D focusses on Dungeons and Dungeon atmosphere suffers if the heroes get to make a quick escape anytime they want to because idf you prssed on as a GM they would end up dead. In the end this latter point is more intrusive to me than the "Captain Fast-Healer" syndrome of 4E. But YMMV, as always.