the problem with the open class system, is that it doesn't matter which class you choose, in the end their all the same. would be pointless to invest any extra class's in that case
That's a misconception. First of all, there
are differences between the classes in DD, and they
do matter: A mage will get much more mana for each point invested in Intelligence than a warrior, for example. Secondly, nobody forces you to mix skills from different classes. If you want to play a pure mage, you can limit yourself to mage skills. It's not like you have to go for the most powerful skills (or the same kind of equipment) with every character. I have played DD with very different characters, and it was quite a different experience.
The open classes make it possible to play the character you imagine, however. If you want to play a trickster who has learned a few magical tricks in addition to his rogues skills or a mage who started as a member of the city watch before his magical talent was discovered, that's possible with DD, and I think this freedom is one of the best aspects of the game.
The skills and the elements weren't balanced, that's true. At first, I thought that was a bad thing because you could waste skill points on skills that were hardly useful. But then again, you get so many skill points that it doesn't hurt to use some for "flair skills". And again, there are enough ways to defeat your foes, you don't have to go for the most powerful (or over-powered) ones like the scorpion traps.
