I'd evaluate your thought process, I have a 6MM ARC and a 6MM Remington. I've been shooting 6MM for nearly 40 years and I am a believer, but I also believe in utilization toward the design, if you want to get a 6MM ARC and love it. Build it and use it closely to what it was designed for, close in deer varmints CQB games.
The 6MM ARC is a military SPR, DMR AR15 cartridge and if you use it in a process that emulates that process, you're going to be happy. An AR15 in 6MM ARC that's 16" or longer will deliver 9MM x 19 muzzle energy at 1,000 yards, over 3 times the energy of 5.56 x 45.
In my experience the 6MM ARCs strong point is that it's a smidgeon better that the 20" AR15 A2. I waited well over 45 years for that smidgeon better. In close in different barrel lengths, it is as good handling as the M1/M2 30 Carbine and the M4 in 5.56 x 45. That smidgeon better is wind performance and energy out past 300 yards.
That does not make the 6MM ARC a 400-yard deer rifle, it is very efficient but a 243, 6mm Remington, 6-06 and many others with equal barrel length will push the heavy 6MM projectiles vastly faster than the 6MM ARC. They will also push light weight varmint bullets so fast that the velocity outperforms the improved BC of the heavy weight projectiles. I push a 75 grain Hornady VMAX to 3,900 FPS.