I'm trying to think back to D2 vs D3 and while I fondly remember playing D2 for... way too many hours, the amount of loot lost due to stutter/disconnects/no shared stash/un-retrievable corpses, original (pre LoD) leveling being a horrible mess, stamina bar, dying to unseen things (fetish darts, gloams)... I wouldn't say it was as good as people make it out to be comparatively.
The talent tree's are definitely better, especially after they made it so they synched with other skills, but it still pretty much came down to the same item driven builds (Titans, frozen orb etc). You can talk to the variations you could make, but there was still the cookie cutter 'best' which was usually 3-4 synchronized skills to your 1 main damage spender + extra/fluff.
As far as story/scenery, they both have their charms. D2's astral space, act 2 tomb style crawls and descent into hell stick out in my memory but the rest seemed kind of dull.
Laughing as I write this, because D3 launch was bruuuuutal. White mobs one shotting you at 60, but when I compare... rune worded out level 85-90 heros being one shot by gloam swarms offscreen, not really different