Although the experiences are similar in terms of F&B offered, the non-Schengen Aegean lounge is small and can be hugely overcrowded at peak hours.

If you have time to spare, you can also go straight to the Schengen Departures area of Hall B. In that case you need to go to security control to get to Hall B, and again through security control to go to Hall A for your Turkish departure - so factor in the needed time. In case someone at security says your flight departs from Hall A and you shouldn't go there, just say that you are meeting someone in the lounge - always works for me. This way you can also access the Lufthansa lounge in Hall A, which has a much nicer offering of food & beverages IMO than both Aegean lounges.