Our boat is based in Preveza and we sail primarily in the inland Ionian
Checked the cruiserswiki.org but in that area it does not compare with Heikells guide to the Ionian.
The wiki has few ports
and anchorages, little information about them, no sketches of ports
or anchorages, none of the hand drawn "maps" that shows you where the main areas of interest are and the few shallows, they are very useful for navigation
Can't find any reference to the shallows between Meganisi and Scorpios, that is one of the few navigation
hazards in the area, it's also in what is probably the most sailed areas in Greece.
The whole Greece guide is big, heavy and probably expensive. If the area is covered in one of Heikell's guide for that area I would get the area guide that is smaller, lighter, cheaper and has a bit more information.