Thanks for a great detailed review Panos, with excellent photography!
I have to agree with Heronimus' and Bolingbroke's comments, this set is not as good as it could have been, though of course I'll have to get it for the black Wyvern unless he appears elsewhere first.
I don't like either figure, they're too much like pirate figures with their over-bright colors. The lack of bracers on the left-hand guy and the silly colors and y-fronts on the blue knight are both off-putting. The yellow sash looks too big to go under the (fur?) collar, so the figure looks like a bad customisation. I like the use of dark grey armor, but as he has a different skin color to every other knight yet produced they've limited customisation possibilities.
I'm not a fan of the big chunky plastic bases either, I'd rather have the figures without that and halve the price, or have a lot more parts to replace it.
I think the Bronze and Iron knights from 2010 were far better designs giving lots of customisation options, and the Dragon Knights and their foes the Green knights were better too. Sorry, these two figures are about the worst Knights I've yet seen. However I may feel different holding them in my hands.