I quit playing in act 3. The game just wasn't getting fun at all, it was a meaningless slog through monsters (some fun to fight, most of them just were punching bags) interspersed with moronic quests. Really, the quests are just too much of the "Go fetch" or "Go kill" variety, and there's no mental stimulation to them whatsoever. It's impossible for me not to compare the game complexity with Diablo 2, with the lone exception that you also have to quest for the NPC that gives you quests, as opposed to talking to everybody in town to see what they want you to do.
I've grumped about the awful skills (1H/1H + shield), and there is no sign that Larian is going to correct those or balance the mana consumption of magic spells, so there's no real incentive for me to play beyond the story. And when you get to the end of act 2, all of your efforts to do nice things for the imps turns out to be a waste of time. <span class='standouttext'>Spoiler : </span><span class='spoiler'>Since Samuel kills every last one of them (except for Tax), why exactly did I do anything about their stupid plague? Why did I rescue that imp from the hole, or look for an imp's husband, or any of that crap? Oh, right, experience points. Huzzah! </span> I had to agree with the Deathknight about the plague -- "A plague? Wish I had thought of that! A plague would wipe out the annoying little buggers once and for all!" It's hard to having a sweeping, epic storyline when your hapless villagers are completely unsympathetic and you don't particularly care whether they live or die.
Without any fun to be had point-clicking on monsters or talking to moronic NPCs for their pointless quests, I'm playing other games that actually have some satisfactory playing experience to them.
As for DD2, I'm unsure if I'll be buying it. DD1 was a brilliant -- but flawed -- game; Larian's done little to fix their policy of releasing flawed gaming experiences, and the brilliance seems to have worn off.