Are the degree options for both edge & base just a personal preference, or is there a preferred angle for icy/granular (New England) skiing?

3 side and .5 base will have you hooking up on that Killington boilerplate just great, but they won't stay sharp all that long. Less acute angles don't get dull as quickly - 2 side and 1 base is probably fine - keep your edges free of burrs and give them a light once over with this tool or a similar tool with a diamond stone every couple of times out. Use a nice stiff ski that's good in that stuff - an all-mountain or "beer league" GS race ski with a 17-20m radius. You want something tighter turning than 22m (older) or 27m (newer) GS skis, that way they'll still be decent on the steep bump runs. You'll never get any edge hold with fat skis - leave those at home unless it just snowed and wasn't windy afterward, which is about twice a year anywhere in NE... Ice is fast and a blast with the right planks.

It's always a personal preference, but for icy you need a more acute edge angle to hold onto whatever you can. For an acute edge, I like my edge at a 3 degree bevel, and my base at a 1 degree bevel.