Both the Vepr and M77 are great rifles. I own an M77 but would probably own a Vepr had I not missed the $499 sale a couple years back.
If you reload, the M77 has an adjustable gas system which can allow it to play nice with some custom loads.
It does not have a chrome lined bore, which probably isn't an issue for most unless you have corrosive surplus to shoot. Barrel is hammer forged.
I don't mind the slant cut receiver much, I put an Ace adapter on mine. The only thing that annoys me is the layout of the side rail. Only a few mounts work well with the M77 Some sit too far back, too high, or don't secure well to the rail. Fortunately there are some Yugo specific products coming out in the last year or so that resolve this issue.
Both the M77 and Vepr don't have a lot of mag options. Csspecs and a couple others are supposed to be seeing M77 mags soon. M14 mags can be modded for the M77, but I suggest doing so with quality mags e. g. CMI. I modded some cheap M14 mags and was disappointed in the results - thin sheet steel in these mags (US Magazine) won't stand up to the bolt carrier engaging the BHO follower, smashing the front of the mag into the trunnion shelf and deforming the spine. Otherwise they fed and functioned flawlessly before the mag got beat up, including last round BHO. . Others who have used the quality mags as a starting point have no issues.
Mine came straight as an arrow with irons out of the box. Nothing canted, no bad rivets, etc. I did clean up the carrier spring channel a bit as there was some rubbing there, and factory trigger needed some polishing work. it's a decent two stage once cleaned up.
Can't go wrong with either rifle