Yeah I ride an SL out here on the east coast too, and I keep going back and forth on whether I should have gotten the Proto. I compromised and moved the bindings around so they stick was twin, and I've been happy.
Well, I don't mind the directional twin. It's only 1/2 inch or so wasn't it? The difference is so negligible to me honestly. When I ride switch, that 1/2' is not noticeable... I mainly got it due to price being $40 less, a nice smooth damp ride, and I found it to be more flexy/playful. Both were great. If the SL had a carbonium top - I would have picked it hands down in a flash without the long debate.