Alexander,
My recommendation to folks is to work with them over extended periods and then go back to whatever they were using. The strength of these boxes is that they are exactly unhyped. After using it for about a week or so... comparatively other stuff just sounds, IMHO, obviously hyped. (Overstatement, but honest). Nice thing is that even at gig volumes, you won't be blasting the snot out of your ears (assuming you have snot in your ears... LOL). Once you are used to these, other solutions (speaking of powered/unpowered wedges - apples to apples) will expose their colors.
The only solutions that can compete with this speaker for me are all starting around 2X the price of these. There are better speakers, but as of yet I've found nothing in the price range that delivers the whole package like these. They are far from perfect; but the RCF NX are very good.
I never liked the K12; favoring the K10 by a wide margin in comparison. Between the K series from QSC and NX series from RCF, it is just a different class/level of gear.
I really enjoy working with this speaker.
IMHO.