I would recommend Naxos over Mykonos and with 12 days you could easily add Paros too. With Santorini, Paros, and Naxos you’ll get a good mix of different delights and some ferry island hopping too which is fun in itself. 1.5 days in Athens is perfect for most – 1 day for the Plaka, Parthenon, Acropolis Museum area; and a half-day to visit the Archaeological Museum which is a short drive or walk from the Plaka but hard to fit in one day along with the other sights.
Kefallonia was severely shaken by an earthquake in 1953 and thereafter lost its quaint gloss. The picturesque northern port of Fiskardo however, escaped much of the destruction and remains to this day one of the main focal points for visitors to the island, so is a good spot for a stay of 2-3 days. Pretty, waterfront cafés and restaurants and a cosy, folksy feel predominate. Asos, between Fiskardo and Argostoli is a west coast ‘resort’ village that pulls in its fair share of visitors and the view down to Asos from the main island road is one of the most photographed spots on Kefallonia.
Located 15 minutes' walk from the Las Vegas Strip, this non-gaming and nonsmoking hotel offers air-conditioned rooms with free WiFi for all devices. Facilities include an outdoor swimming pool. Location was great. Near to everything but not directly in the strip which can be very noisy. Great services such as shuttle buses. Super comfy beds. Great to have your own cooking facilities.