Im with him.My opinion? (Just my opinion and nothing else).
22 arc is such a weird choice in a bolt gun. First thing is that it requires an oddball bolt face that can't be used for pretty much anything else. It will not compete with a 22br in any category, I doubt it will do anything better than a 223 Ackley. If this is about brass then 223 is by far the best choice. Laupa 6br brass is by far the best reloading brass on the planet. Any pennies saved at the beginning on brass using a 22br will not matter after 20 reloads (which is typical for Lapua).
It was a cartridge specifically developed to run in an AR-15. Well... The guy who developed it made it for across the course, and then Hornady pretty much knocked it off, I suppose.
I have people call and inquire about the 22 arc about every 4 or 5 months. Pretty much every one that doesn't go somewhere else goes home with a 22br and is so very happy. Because that's what the 22br does, makes people happy. I would say the 223 makes even more people happy. Because it's just easy peasy and works.
I don't really think the ARC is going to last due to the weird bolt face. It will be a specialty thing for gas guns and thats about it. I would have done a 22br if I didn't have an old doner 223 action to rebarrel to 223ai. Heck, the fireforming loads just hammer.