[Autumn]

Honestly lolzy, I think generally speaking, all of the classes are designed to be able to get through each of the fights eventually, there's no class that has 'troubles' clearing, just some of their clear times can be drastically longer than some others.

When going over each of the classes, and leveling with a friend, a fresh 1-60 run actually, just in the last few days actually, I leveled as Verglas/Demon hunter Hyattr, and they leveled as Demon Hunter/Hexer, even that took a while, and mostly when leveling through that, I felt as if I was doing quite enough damage on that character, everything I did felt satisfying as long as I allocated the right stat points along the way, the only issue that ever arose between us was the general bulk of the monsters, it made it so that we could not do a Crazy dungeon together really without horribly dying, and in the regular dungeons, we felt as if we were competent enough to get through the fight eventually, albeit it taking quite some time, I'll list off a few problems we experienced along the way that could honestly be fixed with only minor tweaks to HP (Lowering the global HP of non boss monsters by say...20%ish)

Survivability: Both of us were playing tank classes that had decent ways of dealing area of effect damage, so it's not like we actually had problems being damaged by individual monsters, both of us usually focused on the nearest monster near ourselves to avoid racking up too much damage on either of us, so that we may regen it after.
This being said, when you cannot kill monsters fast enough and they start to rack up damage against you when they swarm, this applies to damage dealers as well, they'll be taking less damage the longer the fight goes on, cause they can weed out the most threatening monsters with efficiency.

FP Issues: The classes we played had really nice ways to recover their own FP efficiently, so we ended up being able to consistently use our skills effectively as long as we played it smart, but I cannot imagine the same for anyone who does not have a very efficient way to recover their own FP.

Weapon durability: When doing basic attacks vs the monsters with pretty nice above-average damage, each one took anywhere from 5-6 hits before it finally went down, some classes who end up using durability more (Void assassins, Magic Gunner.) will need to carry lots of repair powder, or make constant trips to a repair shop, some have suggested weapon swapping in battle for a momentum cost before, this might help.

Worth: Every battle taking so long mostly led up to constantly asking if each one was worth the time spent into it, each monster taking so long to kill but to only reward a fraction of EXP for each one mostly leads to Crazy dungeons being *ahem* Crazy sources of EXP.

I guess what I'm mostly trying to say here is that almost every class has an effective enough strategy at killing monsters, that much wouldn't ever need to be changed I don't think really, and honestly, if you ask me, the most practical solution is less HP, but more EXP could work out too.

I still think party play is very much encouraged to get the most out of your grinding, the high HP Values have effected this as well.