Ok, it's done. Well, it's definitely a great RPG, no doubt about it. As was pointed out many time before, the world and setting is just so alive and memorable. Especially compared to Divinity: Original Sin that I had played before, with glorious combat but almost everything else being utterly boring, bland, forgettable, juvenile, cliched and pointless.
In Gothic 3, the exact opposite is true. Although I found the claims about the melee combat being "terribad" and "trash" a little bit exagarrated, to say the least. Maybe in vanilla it was really bad but with all the most recent patches and tweaks switched on it is your typical PB combat, with all the pros and cons. Of course the mage gameplay is, as usual in a PB game, simply bad. You just spam fireball and maybe get a few Flamewaves or Ice Explosions in, if you're lucky. But I guess the archer gameplay is just as monotone. Although it is balanced out by the fact that both mages and archers are very weak for the first 1/3 game so Myrtana is a bit of a struggle.
Too bad then that I personally found Myrtana by far the least interesting. So for me it was a struggle through a meh world. I almost dropped the game. Glad I didn't because I found both Nordmar and Varant great. The vistas, the architecture, the mood of the places was absolutely terrific.
So for all doubters my recommendation is - definitely give this one a crack, especially if you like open world. This RPG is as open as they get. Install the latest patch, switch on both Alternative Balancing and Alternative AI. Also, install the content mod. I didn't and sort of regretted it because it gives purpose to a lot of items, ingredients, places and characters that were left unfinished or half-finished in the vanilla, plus it adds a lot of weapons, armors and such. And yeah, go with mage. The first part of the game is gonna be a struggle but by the time you travel north you'll be glad you don't have to hack through the absolutely idiotic number of enemies with melee.