virumor...
I do find it ironic that you say DA is 'just another Tolkien-inspired high fantasy generic world' - well, of course it is. But so is the Drakensang world. There's nothing new or original about that either, and it's a blatant AD&D clone to boot. The DA system is at least developed with computers in mind.
Drakensang is far from a blatant AD&D clone. As I said before, the setting is low magic, which the most well-known AD&D settings (Dragonlance, Forgotten Realms) are not. The setting is also more inspired by medieval Germany rather than an emulgation of all fantasy tropes in the book like AD&D.
If it has to be compared to any AD&D setting, it's closest to Eberron.
virumor...
I definitely agree that Ferdok is a far better realised city than Denerim (or Orzammar, for that matter) but as for the world itself, I thought Thedas was vastly better realised, with far more obvious depth, history and believability than Drakensang. I wouldn't want to live in Thedas, but the clear cultural development, customs and religions made the world itself really come alive, for me. I saw none of that in Drakensang.
In Dragon Age, most of the world's lore is conveniently written down in 'the Codex' instead of shared with the player through the actual game world.
In any case, it's very hard for Dragon Age to compete with any established PnP setting like DSA or D&D which are over 25 years old. The sheer amount of lore in Drakensang just meant that the devs couldn't copy paste all of it in the game like Dragon Age.
Four tanks solved everything in Drakensang. Try that in DA and you'll be dead faster than you can yell 'we're out of healing poultices!' Not only is there better class balancing in DA, but you actually NEED all classes, which you really don't in Drakensang.
Are mages powerful in DA? Sure. but so is a properly equipped warrior or rogue. You have to be pretty high level to start kicking major damage with your mage, and if you get too happy you'll end up blasting your own party by accident. One on one, archers are as good as mages at direct damage, and once your warrior gets there he'll be better yet. Especially if you've given him dual wield, which is just nasty.
Using an all tank party in DA works too, since one can make unlimited health potions (while in Drakensang it's much more difficult to obtain a large amount). In fact, mages make the game so much easier that for a challenge one should probably play without one.
I found that my mage became unstoppable as soon as she picked Cone of Cold spell, which she did in the first town after Ostagar. Freezing enemies followed by shattering wins any battle, since all battles outside of bosses are essentially the same.
I don't understand what you said about archers, they seemed totally useless in my game.
virumor...
But overall, DA is by far the better game.
That's subjective of course, but I think Drakensang is on par with Neverwinter Nights 2, and both to be better than Dragon Age.