DD2 is at least very buggy as far as I can see. And laggy like hell. I mean, I except bugs at a Beta game, but that amount of lag ruins my tower placements quite often.
But they gave 100 gems free this week because they know that the sever has currently issues.
What I really really REALLY hate about DD (no matter which one) is the fact that the enemies drop way too many items. It's ridiculous. It was already in DD1 an issue and they stil didn't learn from it. DD is about the loot, i get that, but wouldn't it be more rewarding to get somethign with a lower drop chance? because after every level I end up with at least one full bag. Making money in the game is way to easy, just sell everything you find.
Also, they still haven't improved the item management since DD1. It's still a mess to find what item fits you the best. How hard can it be to sort items after stats? All I can do is type or rarity but when it comes to stats I have to check EVERY single item myself. So if you want to build for example a tanky character and look for health and armor stats you have to compare every single item for yourself because the game does not do this. It compares only the stuff you wear with the stuff you hover your mouse over.
And you can build tower everywhere. I don't know if this is intended. You can build them on the smallest ledges and on surfaces where enemies cannot reach them. DD1 had a more straightforward tower building system while this is too crazy, there are no specific tower building areas, anything with a surface is fine, even the roof of a market stand.