Two points of contact are the cheek and the shoulder, the Monte Carlo increases the vertical distance of these two points. Line-of-sight/eye-above-bore is the same with a straight stock or Monte Carlo, but the end of the stock where the butt plate is is lowered. People with longer necks may find a Monte Carlo more comfortable, people with short necks may like the standard stock better.
The stock contacts the shoulder, that is the base-line. The increase in vertical distance with the Monte Carlo means the bore line is higher. Heavy recoiling rifles tend to pivot at the shoulder, rotating enough that recoil is transferred to the cheek more than a straight stock.