As far as what it does IN THE REAL WORLD, a low LSA like 106 or 108 will produce more torque, but over a narrower band, and usually at a lower RPM. A larger or "wider" LSA like 112 or 114 will produce lower peak torque, but tends to spread it out over a wider RPM range; mostly upwards. Because it also tends to lower the cyl pressure at the instant when the intake opens while idling, a wide LSA also improves idle quality and produces higher vacuum, which is better for computer-controlled systems (FI).
Therefore you would tend to want a narrow LSA if you can operate the engine in a narrow RPM range and a carb, because it delivers max power under those conditions (think, ½ mile or longer asphalt track with high banking and short straights and wide corners, or an automatic drag car with a converter near trap RPM); but a wide LSA when you want better idle quality, and/or are running EFI.
2° isn't a whole lot of difference. It's kind of subtle. 4° is enough to substantially change the personality of a cam.