Not grumpy at all Morris
Mythos is certainly worth a visit! It's had loads of good reviews and those professional journalist types can describe it far better than me. Have a look at (of all things) the . The review's a bit old now but still fairly accurate.
The one problem with Mythos, as you've probably gathered from the posts here, is it's location. It's right on the harbour side where the road is at its narrowest and just where the ferry docks. Eating at the outside tables as the traffic squeezes past, particularly when the ferry docks, isn't pleasant.
Aktaion is above the gym, a little further along the road. The big advantage is that restaurant is on the roof terrace, well above the noise and fumes of the road and, as Antya pointed out, fantastic sunset views.
I hope that answers your question Morris.
Allan