We stayed in the apartments (self catering) which are just over 1 year old. Really clean and modern and would recommend then. Not too sure what the hotel rooms were like, we heard mixed comments from the people staying in them.
Lassi is a good base for your holiday in Kefalonia. The night life is pretty tame but Argostolli is only a 30 minute walk away and is much more lively. The beach can be quite busy but we found a really small, quiet beach which you have to scale down rocks to get to! We didnt have a bad meal in our two weeks, but one of our favourites was 'Capitol' which is on the scenic road to Argostoli.
We really enjoyed this trip. The beach barbeque was lovely although the Captain does ask you to join in and help chop the salad!
This was our favourite beach, the water does get deep very quickly but it is very good for snorkelling. It is a pebble beach. There is also a really nice beach bar.