Purple Pig is perfect for people who are in Ios to party, who are looking for a cheap place to stay, close to the town and the beach and who don't care about how clean the place is or how well the shower works. But for a couple like us it was not the greatest place, the shower took literally 5-7 minutes to warm up and the beds (they don't have double beds) were very uncomfortable. The owners are very nice though and gave us a ride back and forth from the beach.
Dina's Place is a great hostel and the owner is extremely helpful. The rooms are big and clean and include a safe and a fridge. In contrast to other hostel on Greek's islands the hot water is rapidly functional. They came to pick us up at the airport and brought us back to the port without any charge or advance notice. The site is right in the centre of the town and has a nice pool and terrace. We had a very pleasant stay!
Bunk offers all the necessary amenities but was a bit over priced (for the private ensuite) since our room was extremely small. Moreover the ensuite are on the top floor where everyone hangs out and it can get noisy. The area is great for groups of friends as there are many bars around, but sulthahammet is more appropriate for couple. Wifi is accessible everywhere and is decently fast even on the terrace (there is no more jacuzzi) For the same price you can get something much bigger andnicer
Agora offers a great alternative to regular hotels. We had a double bed ensuite with our own bathroom and it really felt like a hotel room. It was very clean, the staff even made the bed and cleaned our bathroom during our stay. There was a safe box in the room and plenty of space to unpack our backpack. Breakfast was good and was served on the rooftop where you can go enjoy their water pipe which was fairly priced. Location is very good but very touristy and restaurant are pricey