This one I've purchased from Thomann astounds me even now. I use this speaker mainly for vocals. When I was in doubt what to choose Shure itself recommended QSC K series for me. And, man, they were right. I like everything about the speaker, including they way it looks, the sound it produces (especially how clear the sound is), how big the sound can be (I've heard it can reach the sound of a Boeing on max volume but haven't tried this yet, only on low to mid volumes).
Jordan Rudess from Dream Theater uses the QSC series for his instrument, the keyboard, also for presentations. He admires the QSC for having 'a crystal clear sound'. He also told that these are the best ones of anything he has tried.
I would definitely go with this speaker,