Matsue worth 8 hour train from Takayama?

After the Takayama festival we want to make use of our rail pass and have 2 nights April 16 to 18 - I thought of taking the train to Matsue for 2 nights, before returning to Tokyo. Or is it better with 1 night Matsue and 1 night Tottori? We have been to Kanazawa, Kyoto etc. and need something interesting for April 16 to 18 - like historic Japan and nice scenery but everything would have to be close to JR station due to difficulty walking.

If you have difficulty walking, I don't know if I'd recommend Tottori. The sites are spread out, and part of enjoying the sand dunes is walking on and through them. It depends on how bad your walking condition is, though, and of course you could adjust how much you walk according to how you feel and what you can handle, but I walked a lot in Tottori.

Matsue's sites are not near the station, but they have a bus that loops around to the most famous sites. Their website is very useful with the transport info:
http://www.visit-matsue.com/info/moving.html#bus

Maybe combine Matsue with Okayama/Kurashiki if Tottori won't work out.

You can visit the garden/castle in Okayama and then stroll along the canal area in Kurashiki. You can either walk to the castle area or take the tram if you're feeling tired. Though I would suggest at least walking one way so you can see the statues from the Momotaro story along the street.