I don't think it makes any difference. The kind of pax who are going to panic will do so regardless. I've seen it countless times here, where we have the Dash 7 & Dash 8 (cockpit door closed), and Twin Otter and Caravan / Grand Caravan (no cockpit door) operating the same routes. Pax who are claustrophobic, have control issues or simply don't like being tossed around in a smaller aircraft when the bumps come, have the same reaction regardless of equipment type.
Personally, I love being up-front / seeing what's going on up-front. But then, that's why I'm learning to fly.