We just did Black Sea last Aug/Sept - and loved it! Such great ports - we were the only ship in every port except Athens, Ephesus and Istanbul. It was great to be off the beaten path. I highly recommend this itinerary. Who knew Nessebur, Bulgaria would have an amazing church ruin on every corner? Odessa is such a charming city.
Yeah, Athens will be hot and humid. But, that's just one city. For us, Sochi was hotter than Athens (and Sochi's where the *winter* olympics will be - still trying to understand that).
You won't regret taking this cruise. Please ask if you have any specific questions - always happy to talk about past cruises!
:)
Liz