J. Sawyer's talk about 'going in blind' being a negative, being forced to reload, etc, as a strike against memorising spells, seems slightly wrongheaded. I think someone mentioned earlier the idea of giving the player signals about what lay ahead, but it doesn't even have to be that explicit. The D & D player party wanders into an ancient temple filled with many-eyed statues. 'Aha,' thinks the player who's both engaged in the world and actively planning ahead, 'I should prepare for beholders. Let's head back to that old gypsy caravan and pick up some scrolls/open up my mage's spellbook and figure out how to counter them/maybe try and recruit that mad old wizard back at the inn so I have some scope'. Perhaps a local villager has the head of one of the local monsters on their wall; perhaps the local library contains scribblings about viable tactics against such beasts. If your party's about to face a central villain, presumably they've heard a little or seen a little about the spells and defences they're likely to use. There's absolutely no reason, in short, why memorised spells should lead to save-scumming or blind guesswork, so long as the encounter and dungeon design is good, and as long as the world is communicating with the player. That's not an inherent problem with the system.
A great joy of the RPG genre always has been the play on heading into the place of relative safety in order to prepare for the place of danger. The party returns to town/rests in the wilds/heads for the local temple, and prepares themselves as much as humanly possible for whatever challenge they believe they're coming up against next - they build up their resources, then carefully expend and conserve them as they enter the dangerous places (You fool! You just wasted your one Cataclysm spell on that Feeble Earthworm! etc). Memorising spells works splendidly with that dichotomy, though as we've seen here you can then get into concerns about the ease of resting, etc, and can even subvert it for genuine desperate thrills (aargh, we've just been ambushed with no healing spells left, how will the Heroes of Bummington get out of this scrape?) whereas cooldowns, depending on how they're implemented, can kill it stone dead.
With cooldowns, the town/camp/tavern/temple/safe-place loses the entire core of its identity. You lose the sense of relief as you limp back into the cobbled streets of Thingy - why would you be relieved? Your spells are all ready and waiting once again; your party's main requirement is now to survive battle-to-battle, not to survive long enough to reach that place of safety or to be able to rest. The only real remaining purpose of the non-dungeon-area is to serve as a shop/loot-storage-area; it's merely functional, it's no longer a blessing. And actually, it's interesting that the cooldown-based Dragon Age games were forced to try and invent dubious reasons to try and keep the safety/danger dichotomy relevant (you have to rest in-camp, because dying in combat can sometimes give you a small HP reduction that can only be removed in camp! You have to go home because you're not allowed to talk to your party members outside of home, for some reason!) before giving up entirely and making the town itself a dungeon; every time you step outside, thirty muggers attack you. Once you're done killing them, the merchants standing around will become selectable again. Something very special is lost in the process here.