I'd say it's an acquired taste. Either you like them, or you don't. A lot of people here like them, and a lot of people, well, don't. My best friend doesn't like them at all, and I throw at him all kinds of music I like and that's basically how I introduced him to Steven Wilson, Agalloch, Wolverine, Leprous, Ayreon; he loves all those bands but he doesn't like Haken. I, on the other hand, love them. They're a breath of fresh air in a prog metal scene.
I travelled to Hamburg to see their show and do a meet and greet with them, and it was worth every penny and then some. I had a blast chatting with them, and the show was fantastic.
Another thing I wanted to kinda mention, I love how diverse their T-shirts are. For Vector tour, I have a beige one, a red one, a black one with green/orange print, the black with insects and then I also bought the green Heineken/Haken one because that one is pretty good. I think among all the bands Haken is the one I own most T-shirts from.