Firstly, if you're travelling to Kilberry from further south in Kintyre, don't underestimate your journey time. The road from Tarbert is slower than you might imagine, especially if the weather isn't great! We drove up from Campbeltown for lunch and arrived half an hour late, but they were very understanding (we had not been able to get a phone signal for the entire journey) - it must happen to them all the time!
The restaurant was very quiet, though the bad weather may have kept people away, but it was very stylish, warm and inviting, with exposed stonework and an open log fire. The lunch menu is, typically for a well-run restaurant, very much a reduced menu with three or four choices for each course. It was mostly locally sourced fish, with less emphasis on the local meat and game which were in evidence on the evening menu. Though this was a pity, it was perfectly understandable, as this kind of menu does mean that things can be cooked fresh to order.
It was a delicious lunch, and probably the best food we encountered on the entire Kintyre peninsular. We can't wait to return in the future and stay for an evening meal (the Kilberry also have several, lovely bed & breakfast rooms!)