I couldn't get the hang of the "V" sight, and didn't want to waste too much 75-cent per round ammo figuring it out (I haven't ordered ammo for it in bulk yet so I'm shooting Winchester Super-X through it ... $$$$$$$). But the peep sight worked beautifully -- much more intuitive to me than my AR (which has A1 sights) ...
PTR has rear sights with a 100 yard aperature. I bought one and replaced the V notch rear sight.
They also sell a bolt tool, which I think is great. It holds the bolt head spring down while you slide the bolt head on. My bolt has a monster spring, and it is difficult getting that all together without the tool.
As for elevation adjustments. Look around for needle nose pliers that will fit into the rear sight notches. I found a set in my garage. This is a cheap solution, sometimes frustrating because you have to push in two pins at the same time, and hold them in, while you rotate the turret. You need three hands to do this, one to turn the turret and two to hold the pliers in place. Having only two hands I found the pliers will jump out, or I had only one pin pushed in.
I do recommend getting the port buffer.
I like my PTR, it is a great rifle.