Only issues I've had with ARC mags were if they got dirty, such as if I dropped them or if it was a particularly dusty day with lots of wind. As a result I usually toss mine in an ultrasonic cleaner whenever I get home from the range or a match, keeps them cleaned up nicely, and then if one of them gets dirty during the day (I dropped it or something) then it goes back in my pack and I use a different one.
One major benefit, IMO, of ARC mags that is rarely discussed is that their shorter feed lips allow you to feed BR-based cartridges (BRA, Dasher, etc.) without any worries about spacer kits or using different magazines for different cartridges. I've used them for the last 4 years shooting both BR and Dasher and never had any of the typical BR feeding issues, just load them up and shoot same as any other cartridge.
One thing I did also notice is that when I first experimented with graphite as a lubricant while seating bullets my ARC mags stopped being so picky about if they were dirty or not. Instead of dipping the entire case neck in graphite (very dirty) I just dip the base of each bullet into the graphite and seat. Still ends up with a little graphite on the bullets and brass, but less than dipping the case itself and I never bothered to wipe it off. Turns out that graphite that ends up on the cases from handling (I pick up the rounds out of an MTM case by grabbing the projectiles, getting graphite on my fingers, then load into the magazine getting graphite into the magazine and on the brass) makes the ARC mags feed super smooth. First time I went to the range after loading with graphite I actually thought my magazines were binding up because I couldn't feel the action picking up a round at all when I cycled the bolt. I also tested by intentionally dropping my magazine into the dirt several times while only giving it a quick wipe inside with one finger and it continued to feed without problems, but I still replace for the day any magazines I might drop just out of an abundance of caution.
I didn't notice any difference at all in my ammo (consistency or group sizes) by using the graphite, but I liked how it made my ARC mags run super smooth and more reliably so I have continued to use graphite ever since. It leaves your hands looking like a mess at the end of a day of shooting, but it's not like I don't wash them after shooting anyways to get rid of any lead/carbon that's there already.