We are spending 4 days in Santorini in September. I have already booked accommodation in Naxos for 4 nights also, however, are having second thoughts and considering Paros, possibly Naousa area, as I have been told Paros is more lively and has more to offer than Naxos. Without being to either of these Islands before, it is hard to determine which is better suited to us. We are early 50's, like to do the cafe/ restaurant thing, walk through local villages and relax. Any advice or suggestion would be greatly appreciated.
Naxos and Paros are very similar. In general they are equally as appealing. I prefer Paros, and the main village of Parikia is where I recommend you stay if you want easy access to "lively". Naoussa is a lovely area but nowhere near as lively, especially in the evenings.
I really can't imagine that you'd be disappointed or bored on either island.