In general, it was an amazing experience and I learned a lot. The only thing that I would change is to introduce the topic of lesson planning (language awareness and all) during the first week (preferably the first two days) so that trainees would know what to do when planning the 1st TP.
Excellent course, run by enthusiastic and supportive tutors. The CELTA class size was just right and the student groups we taught were also lovely. I'd recommend both the course, and Athens as a place to study.