Never really got into D1 - played it for a couple of months, but had D2 since launch. It fills a void for me. Good co-op fun. It's more of a jack of all trades than excellent at any one thing.
1. Enemy archetypes need improving. So fed up of cabal and fallen psions by now. The taken are just shadow versions basically. I was alreayd fed up of Vex from d1.....
2. The game is not a looker by any stretch. I play on the Pro and some if it looks decent but under any scrutiny textures are poor - in my opinion.
3. Solo players can progress quite easily - they don't need the nightfall or raid, though they help. Being part of a clan as well. Usually the Flashpoint EDZ and an hour of crucible can get you powergul gear at end level.
4. Co-op is good. They need to improve guided games. The clan app is terrible, needs improving. Also need clan management tools, to see who is active/contributing XP etc. so you can kick inactive because of the 99 player cap (100 if you don't want to run guided games). I might be ignorant of such management features I'll concede.
5. The loot is largely terrible, how many times does Prophet Snow need to drop? You have a few tweaks with the +5 mods etc. but the loadout will be pretty standard when you hit endgame. Might swap between one or two depending on endgame modifiers. I'm reasonably happy with the different types in the game, but none of them feel hugely different. And the perks don't differentiate them enough
6. The infusing/upgrading weapons is boring and awful. Base power and +mod power need to be more clearly defined in the UI. There should be other ways to improve the power in your weapon by using it at end game level rather than RNG drops and infusing. I don't think I've had a trace rifle drop in the last two months so can't infuse......
7. They need to add more content/scenario's for public events. There are like 5 or 6 I think and some are recycled from d1 (walker)? Really, that's all we get - even something like a basic horde mode would be good.
The core of a really good game is there. The jump from d1 to d2 was not big enough in terms of content, and is actually a step down in the eyes and words of those who played d1 for a significant amount of time.
I'd say it's worth jumping in, although I'm not sure what they've done with the XP. I thought they modified it only for those earning bright engrams but if the normal slog to level 20 has beocme more of a grind, I'd be tempted to say pass.