What sling is that, OP?
I really like my ARX. At first, I was very unimpressed with the "feel", which I could only describe as unusual, the heavy trigger and the "Stevie Wonder" sights. I added the 6:00 rail with a Magpul Hand Stop and replaced the factory sights with Magpul MBUS Pro's. Now, the more I shoot this gun, the more I like it. The trigger pull is heavy, but it's just fine for a defensive carbine. That said, the trigger itself is wide and I'm able to pull it pretty fast
. I like the adjustable comb on the ACR and SCAR, but the ARX's stock is much "tighter". I had a little trouble finding the proper mount/height for my Aimpoint. A true cowitness mount was too high, so I went with a low Aimpoint QRP mount, which gives me an upper 1/3 cowitness. I don't spend a ton of time worrying about cowitness, but the upper 1/3 is kind of quirky. The ARX is very light and it feels very much like a SCAR to me. There is a noticeable forward "jump" or "jolt" when the weapon goes back into battery and the action itself is very perceptible. My biggest gripe is the A2 pistol grip and I would very much like to have the "shelf" removed.
They can be had in the $1200-$1300 range, which is a great value. SBR kits are available, and those too are affordable. Supposedly caliber conversions are forthcoming, but as an ACR owner, I'll believe that when I physically see one. That said, I have a high level of confidence in at least a 7.62x39 conversion due to the existence of ARX-160's in that caliber.
While not my favorite "non-AR", the ARX-100 is a great gun and I don't regret spending $1200ish on it. Now if only I could find a sling I like...