Despite some issues Diablo 3 is the best in its category out there..
Gameplay : More or so the gameplay of D3 is the way we remembered it with some advantages and drawbacks. The inventory for example can hold much more items inside which makes it much more easier. for example the chest armor only occupies two blocks and not 6 (if i am not mistaken) as it was in diablo 2. A major drawback is that your skills are somewhat "predefined" and you do not have a skill tree like d2 and no attributes to change. On one hand this improves the balance when it comes to online play and there can be no exploits but on the other hands it kills unique characters and reduces the lifespan of the game as there is no reason for extra game time for twicking.
Length :
I have heard people saying that they have finished this game in 4 hours...And i wonder how can that be possible since it took me more than 5 hours in order to finish the first act...Even if you try to play like a mad man (and loose all the beauty) you cannot finish the game in 4 hours. these people are trolls and try to find a way to make this game look Bad... If the acts are as big as the act 1 i consider that this game is as big as it was d2 if not, bigger (you cannot make 12Gb game for 4 hours of gameplay and this is blizzard). I mean, there are people that saying absurd things... One says "click click click reward...click click click reward... " thats diablo my friend, thats the essence of hack and slash. If you dont like it you should try neverwinter nights. Some people have even given it 1.0 for they were unable to play yesterday due to server overload...Come on people this is not a way to judge a game. Since i was also one of the people who weren't able to play, i do understand your anger but i also find your score quite harsh.
Online experience :
Ok... The online experience is really fun to play. With one click you can team up with people or friends and you can play online any missions you have finished or advance together. There is also an auction house where you can get anything you need (or not, for its optional) and soon there will be a choice where you will be able to sell your items in real money if you want (which is a choice too). I find this idea very nice so you can trade any item you will find (but you wont be needing it)...As long as the "real money" issue is just a choice and not a must, i call this idea very nice.
However online has its drawbacks too.... For example, why am i forced to play a game in single player mode that was ment to play offline and have to be online as if it was an online game? I find this outrageous from blizzard's part and they should give to the people the chance to play the game offline if they wish it. I dont wish to be logged within the blizzard servers all the time as if i was playing online while i play the game in single mode... A single player game with online drawbacks? Really? Ubisoft made it with Silent hunter 5....Now blizzard should do it (for their own good).
Overall :
I think this game worth its money and its WAY the best choice for a hack and slash game. It is fun to play, it has good mechanisms, it has (so far) a good scenario, it has an outstanding atmosphere, millions of items, nice music..... It can keep you occupied for a long time. But if blizzard wont act more wisely in some terms i am afraid that even though this game has the potential to be another diamond in blizzard's games, it will end up being the "black sheep"