How important are these? When dealing with cheek pieces, should I go with the hard plastic style which require me to drill through my stock or just the velcro cheek pieces, like the ones made by Triad Tactical?
Whatever cheek piece you use I recommend a hard and super secure as opposed to anything Velcroed on.
The scope level or anti-cant devise is critical at distance as your scope adjustments are assuming your scope is directly above the bore and depending on gravity to intercept poa and poi at a given drop.
So if your canted you could be adjusting up and left or up and right instead of just up. This minor discrepancy is compounded when you start dialing for distance and the more adjustment you put on the scope the farther away from the center line you will be.