ASC vs GIK?

I have experience with GIK and Artnovion Acoustics. There are no absolutes with audio and every system/room is different. In my room/system the Artnovion improves bass articulation, allows me to hear further in the soundstage, with better spacing between instruments. Aesthetically Artnovion panels look significantly better and their quality makes GIK panels look like DIY panels. Of course it's just my opinion.

I’ve had diffusion and scatter products from both companies for several years in a large dedicated 2 channel listening area. The build quality from each company is equivalent — striving for mediocrity. Their functionality is equivalent — they’ll enhance your listening experience. In hindsight, I’d have them built by a skilled woodworker. The need to engineer these simple designs is laughable. They’d be a fun high school woodworking project. 

These panels are basically wood and insulation covered with fabric.  There isn't a ton of difference between them, even if their marketing gurus try to sell you otherwise.

If you're not liking the results, perhaps you like the sound of a more lively room?  First reflections (including ceiling) will do the most to dampen the sound and make the room less of a factor.  Bass traps (the larger the better) will absorb bass which should make nulls and peaks more even.  I use giant 21" chunk traps in my corners that go from floor to ceiling.  And then I use soffits from those to the rear chunk traps.  I built most of the paneling myself with some help from GIK for the diffusion.

Take all the paneling off and see if you like it better.  If so - DO NOT go buying panels from someone else.  You just like a more lively room.  Maybe you can get by with JUST the first reflections being covered?  Try that and see if you like it.  Otherwise, I agree with others that are asking have you been measuring the response and the RT60 before and after paneling?  Maybe the frequency response is dulled now.  Figure out the issue before trying to throw more paneling at it!

@jrareform I have floor to ceiling corner traps in the corners behind the speakers. 
There are also panels at the 1st & 2nd reflection points. 
Since I use Magnepan speakers, it is a bit more challenging to get the acoustics to have the right balance between absorption and diffusion. At first I did have too much treatment and gradually removed it. 

I am afraid I actually have very strong opinions based on listening experience at a show. 

I attended a show near Oakland, CA ages ago, sponsored by ASC acoustics.  Most rooms were heavily treated with ASC tube traps, regardless of size.  A few were not.  Fritz, interestingly, was not using them, but he came with a handful of flat panels. 

My experience after listening to at least a dozen rooms with ASC tube traps is that the rooms all developed one-note bass.  The bass sounded exactly the same no matter the music.  Very much a disco/thumping kind of response.  I believe that this has to do with exactly where they dampen.  It’s kind of a broad mid-bass suckout, leaving the thump, but removing anything else.  For me this was not good and also, very expensive. 

I’d usually strongly suggest you invest in ATS or Gik instead, and depending on what exactly you need.  If you have really low room modes that need control Gik has some of the best performing soffit traps and corner traps out there. 

For general room taming absorber panels I’d go with either.  Gik has in the last few years also added a line of combination diffuser + absorber panels.