I have an M85 and love it. Getting 2" groups with surplus ammo and pretty much any hunting ammo I put through it - it's a shooter.Getting 2" groups with a hunting rifle off sandbags might not seem like much, but with the quality of surplus ammo - or the commercial ammo out there for that matter - it's a sign of just how good the barrel is. With handloads (which I couldn't be bothered with for x39), I have zero doubt it would be a 1" shooter.
As mentioned already, the adjustable trigger is a thing of wonder. I have mine set at a clean 2lbs, with no takeup, overtravel, or creep. Absolutely crisp 2 pound break.
I got the Stutzen Stock version of it, it's it's a 6lb, lightweight, easy pointing little carbine. The wood finish could have been better, but this is going to be my go to bush hunting gun, so it will get abused anyway.
So... Given how easy it is to point, and how good the trigger is, those 2" groups off bags on the bench are easily going to translate into a freezer full of meat this fall.
Also - CZ v. Zastava:
The fit and finish on the CZ are better. But the single set trigger just isn't something I'm used to. And as for detachable box mags? It's a hunting rifle. A box mag is just something else to lose. I'd rather have the internal mag on the Zastava.
The Zastava kept an extra $300 in my wallet to blow on other things. The CZ is a good rifle. It certainly isn't $300 better.