Bought this game months ago but never finished it.
Only just now got back into it thanks to DLC hype (though I haven't bought it yet).
Went in sort of wondering what made me drop it at different times in the past.
After finally getting past Giant frosty mountain and deciding to go fight everyone, finishing the game and then starting a new game with a different character I think I got a good grasp on why I had lost interest. Nothing I'm about to say is particularly new, but I agree with those that don't find the giant expanse all that great. It certainly looks pretty and as far as open worlds go it ain't bad, but it's unrewarding to cross vast regions, kill dozens of enemies and kill a boss just to end up finding things you can't use. Of course, you can explore and fight for the sake of it, which should be rewarding in and of itself which is where my biggest gripe comes in. I just don't think the combat holds up.
Others have spoken about wack bosses but rather than difficulty I think the problem is the really bad pacing and reward. I've got more than 2k hours in both Nioh games and probably just as many in the Monster Hunter games and the reasons why are that those games have what I would call rewarding combat. For comparison, I've played DS1 and 3 and found both to have more enjoyable bosses (with a few notable exceptions) despite their relative simplicity compared to ER where about half the bosses aspire to be Nameless King.
None of the tools the ER bosses use are evil by themselves but when they load every cunt with gotchas, variable combo enders, input reads, etc. they make very dull battles where I don't have any real initiative to do anything. This results in romantic moments where me and the boss will lovingly stare into each other's eyes for 5 full seconds before something happens. Watch in stunning amazement as a boss steal turns again and again by stopping his combos just before the punishable ender or cancelling his recovery into a rocket fart propelled leap into orbit or a 20 foot side step with 2 full seconds of invulnerability. Then, on top of that, if you respond by attacking when you think he's canceled, he can cancel the cancel, since some will counterattack as an immediate response to you having the audacity to want to play the game. Even when I can fight a boss with my eyes closed it really is godawful just watching enemies complete whole feature length choreographed dance routines just to be rewarded with gentle yet firm slap on the enemy's ass. That kind of thing should be reserved for one's wife.
In the other games I've mentioned there are bosses like that, but the respective communities correctly calls them out as garbage bosses. AT Nergigante has a move that could be called his Waterfowl Dance and just like with WD everyone hated it. The whole fight with Nerg is dominated by a single move that's actually even worse than WD because he can cancel recoveries into it, it's one of his fastest starting moves, has relatively fast recovery, is homing and even with full health and defense buffs deals 80% of your hp.
Something both Nioh and MH get right is the reward for doing well. In ER you'll watch 10 second boss cutscenes over and over and when you finally poise break you get at best 2 button presses and a pre-canned 2 seconds too long animation you got tired of seeing hours ago. In Nioh, you drain stamina, then start performing MarvelvsCapcom combos on the guy. In MH you'll score a knockdown and the moves you can now use feel suitably powerful, adequate to the effort you spent getting that opening.
Now, I haven't played the DLC, but I overall found both Nioh2's late game and certain specific fights in MH to be harder than anything in ER but I still enjoyed those bosses.
I think the real issue is something that, while associated with difficulty, goes beyond it. The short version, I just think the bosses and many enemies aren't fun to fight. I would venture to say they play much better when you allow yourself to use spirit summons since the insanely unpredictable aggro giving you some openings helps the fights feel more active. It is true that some summons are just so busted good that they trivialize the fights but let's be honest, ez mode builds and tools aren't exactly new to the franchise.
I'll keep fooling around on my new character and see how I feel after awhile before deciding on whether to get the DLC now or wait till a sale.