agree with Pijal,
put aside all the connection problems, it is a great game.

Story. The story, voice, environment and animation does make D3 is more alive compare to D2.

Character System. At first I hate they remove the stat/skill customize, but I realize as my life is busy, each class only train once really sounds good to me, if i want change play-style just change skill & equipments.

Battle System. No major change from D2, rush rush rush then face elites/champions.

GamePlay. No major change from D2, also 4 acts, it is not Dragon Age and heavy story game, but rather the Diablo series core gameplay is still based on equipment finding.

Graphic. It is presentable enough to interpret the diablo world and run smooth on my PC

Yes, compare to D2, lot of things are removes, but as a busy employee I feel that it is more fit to the market, so i guess they are doing the right thing to keep the number of players. If too complicated and hardcore, maybe scared new/busy players away.