Im flying out on Viking on 3 July to Volos via Skiathos and back on 10 July from Gatwick.
I have to say I have been most impressed by the correspondence I have received so far.
We prebooked our seats (1C and 1D on the outbound and the two seats together on the return by themselves). It appears that the return journey has been amended from a 737-300 to a 737-800 and we received an e-mail asking us that due to an aircraft change could we reselect our seats.
I will post an update when I return on how the flights were - I am flying with a nervous flyer so that should be fun.