Haven't stayed at that hotel, but have been to Kefalonia 5 times stayed at mounda near Scala. When we went in September, it was glorious, still quite hot although it got darker earlier in the evenings. It was quieter, more relaxed and the sea was lovely and warm. The tavernas were winding down a bit , so the staff were more relaxed and happy. You must go to katelios, little fishing village just round the corner from Scala - beautiful, a row of tavernas and bars on a small stretch fringing the sea one side and countryside the other. A good choice of local food here, fresh fish brought in by the boats moored right next to the beach. Each taverna is different with outside seating, fairlights and just the sound of sea on the shore and windchimes tinkling on the fishing boats.
Mounda has a long sandy beach unlike Scala which is shingle and shelves quickly into deep water, so swimming we found better there. Scala has a good town with everything open til quite late Good little supermarket for essentials and ouzo was cheap there for taking home!
I think we had a very good time on our Sepetember trip, it was more laid back and we went across to Ithica then from Sami which was fabulous.
You'll have a brilliant time.