Milos

I went to both Milos and Meteora on my recent trip. I posted a thread called Three Weeks In Greece in the Trip Reports section--haven't gotten to Meteora yet.

Milos -- probably will want a car. I stayed in Pollonia on the NE part of the island, about 10 km from the port town. I enjoyed Sarakiniko Beach and Paleochori Beach, the catacombs and ancient theater, the fishing village of Klima, and my boat tour. My boat tour left from Pollonia and went to Poliegos rather than the majority that leave from Adamantas, go around Milos and visit the famous Kleftiko caves on the SW corner of Milos.

Meteora--I actually stayed in the nearby city of Trikala for 3 nights. It's about 20 km from Kalambaka & Meteora. I think Trikala is a great little city and you could consider staying there or at least giving it a day trip. In Meteora, I took a hiking tour that was focused on nature rather than the monasteries, so I didn't actually go inside any of the monasteries, although I did go inside some of the old hermit caves. I also did a sunset e-bike tour and that was great! I visited the Natural History & Mushroom Museum in Kalambaka, mainly because it was super hot that afternoon. Unless you really like stuffed birds or mushrooms, this isn't a must-see.

Even if there were no monasteries ever built at Meteora, I think it's awesome just from the geological standpoint.

Milos is fairly small and has some great beaches. As mentioned a car will be important in Milos as the bus system is set up for locals. With a car you can easily explore the whole island. While September is becoming almost high season Milos will be slowing down. The car gives you the option of staying in Pollonia, Adamas or Plaka. We stay in Plaka because it is a traditional Greek village while Adamas is the port and capital and Pollonia is primarily a beach destination.
Here is what Milos is like.
Milos http://www.flickr.com/photos/stanbr54/sets/72157632109429236/
Milos http://www.flickr.com/photos/stanbr54/sets/72157634779985764/

How are you planning on getting to Meteora? If you are flying to Athens after Milos then you can take advantage of car rental at Athens airport. It will be about a 5 hour drive to Meteora. Plan to arrive about a half hour before sunset. all the tourist buses will be gone and you will have unobstructed views of the monasteries. The next day get up early and be at the gate of the monastery that you most desire to see.
Once the tour buses arrive the whole area is just crawling with visitors. You will be glad you got your overview of the area the evening before.

We stayed at the village of Kastraki. Its nestled at the foot of the monastery mountains and the views from there are amazing. Its proximity tot eh Monasteries means a short drive up and gives you the jump on the tour buses.
Delphi and Meteora https://www.flickr.com/photos/stanbr54/albums/72157698930270992