No expert or phycisist, but here's what I think anyway....
At 0* base bevel, skis with an aggressive sidecut will be very "hooky". In other words you'll be catching edges every time you fall asleep in your boots and twitch to one side or the other. And the very nature of ski slopes not being uniform adds to the chances of catching those edges. 0* requires 100% concentration and precision all day. Not much fun, but that's what the skis are designed to do. The very design structure that makes them so much better at holding an edge in hard snow than straight skis, requires some design slop (base bevel) to keep them from being unmanageable. The more precise you want to be, the less design slop you want.
A 1* base bevel is a nice compromise between precision and slop. I assume this is why most manufacturers go with this as the factory tune...the setting for the masses. It allows some feathering of turns, but also allows the ability to angulate to the point of engaging the edge without overdoing it.
Adjust the base bevel from there....if you spend your days perfecting slalom turns on a generally hard surface, go down to 0.5*. If you spend your time traversing in uncut to get to the goods, experiment with greater base bevel angles. Understand, though, that your groomed performance will suffer at a rate that is probably exponential in relationship to the amount you change it. I realize that many of the folks in the west couldn't care less about that.
Not so sure about this theory, but I'll throw it out anyway to keep the discussion going. I see a trend in "Big Mountain Skis" toward SG and DH turn radii. As these skis approach the turn radius of the old, straight skis, the base and side edge bevels can head back toward 0/0 with no ill effects. Any thoughts on this theory?
Alpinord pretty much covered the relationship between base and side bevel angles.