Gythion is a nice little port with not a whole lot going on and that why I like it. Here is the real Greece away from all the tourist hype. The beach is nice and deserted and the accommodations while not luxurious are decent. The food is fresh and the people friendly. You could do a lot worse!
Don't you be Contacting me for ferry schedules now! Look on the internet like everyone else does and be aware the boats to Crete do not run as often from here as they would from a major port. Maybe twice a week, maybe more in August, the peak period.
Still, exploring the Peloponnese and then departing for Crete from here lets you visit all the Cycladic and Dodecanese islands without having to return to Piraeus to get there. Its a great alternative and the less traveled path. You may have to hole up in Heraklion or Hania and wait for a boat but that's fine too! Don't forget ferry schedules are not etched in stone - the weather plays a huge part!