I stayed in Hanioti in 2005 and spent an enjoyable day in Polychrono (and Pefkohori). The two resorts are just about close enough to walk although taxis were only 5 euros.
Of the two we personally preferred Hanioti. We like places to be bustling and lively, although not 18-30 style resorts, and Hanioti was certainly the busier of the two with lots of bars and restaurants to choose from. We found our evenings could be as lively or as quiet as we wanted. The bars that were playing music were not overly loud and wouldn't intrude on a night out if you wanted somewhere quieter. We also thought the beach at Hanioti was much nicer.
The restaurants that we visited were of a high quality and theres a number that I'd recommend. Hanioti seems to attract a mixed range of holidaymakers although we didn't really see any big groups of lads/girls.
Hope this has helped a bit!
Steve