Greece wasn't our favorite country (which doesn't mean you won't love it) and Ios contributed to 90% of the dislike.
Naive and little as we were at the time, we gave into everyone's "omg but you MUST go to Ios, best place ever!! the parties there are out of control!!!" etc etc. What we really discovered was an overpriced island (beautiful as it was) full of drunk Australian teenagers (and ridiculously sad 20 somethings) wearing bar hopping singlets. There were also a distinctive breed of males who enjoyed the obnoxious yet 'classic' chant of 'yeah the boys, up the boys' and made sure the rest of the island knew all about it...
I like a good night out as much as the next person but I can safely confirm there was nothing GOOD about Ios nightlife. I am fairly certain the only reason people enjoy themselves here is because they spend the entire time completely off their head... no backpacker in their right mind would think it a plausible idea to spend 25 euro on a bar merchandise singlet.??
Anyway!!! Ebbs and I spent 5 nights here because it was peak season and so I had pre-booked everything and we couldn't escape (without loosing lots of money). We were there in late August which we were told was 'the end of the season' so the town was a little quieter than usual (thank god). The island is pretty small and has one main town called Chora and several beaches in its different bays. The main mode of transport is bus and quad bike.
To get here it is a 40 minute ferry from Santorini which cost 60 euros.