They are a bit ammo fussy. I'm getting 1 moa groups with 168gr GGG, but the groups with Ball ammo were all over the place. I'm sure I could get sub-MOA if I homeloaded and refined my ammo. But I'm happy with it as it is. Was hitting targets up to 800 yards. I was only limited by my scope elevation to go further. But I'm ultimately looking to stalk with this eventually, so that's good enough for me. The 6.5 Creedmoors tend to give better groups in general.
I've heard a lot of good things about Proof barrels, but I'll probably only consider them once I've worn this one out. How much did it cost you, and what was the wait time?
I guess everyone who owns one loves them, hence why they don't go on sale as used. I've seen more Q the fix on second-hand sale than these.