We weren't planning on visiting Ios at all this summer, but a friend of mine was there with his girlfriend and told us to come down (we were in Naxos at the time)
Mylopotas (the famous, long sandy beach) was quite pretty when we first arrived. We found very affordable and clean accommodation, the locals were very friendly, the food was good. The Ios Palace Hotel was very nice and has some beautiful views of Mylopotas. The Far Out Village is actually a fun place to hang out during the day. It's a mixture of camping (which, by the way, is quite affordable) and hotel rooms.
Now the Chora, that's a different story - insane partying, a pretty "youngish" crowd whose only interest is getting drunk & lucky. We luckily found some nice "Greek" barakia where things are calmer and you can have a good time - it's getting to them that's sometimes difficult, when you have to step over all the drunken people...it's actually quite a sight to see. It's definitely worth seeing the Chora around 9:00pm before things get out of hand - very picturesque.
Ios is a beautiful island worth exploring with many beautiful beaches. At first, I was turned off by its reputation but found that you can actually find peace and quiet and not have to venture into the Chora at all. I will definitely go back and recommend it!
Just my 2 cents!
FYI - Ios doesn't have an airport.