Just back from that general area of the Med, including spending a week in and around Elba.
This was in August when there is little chance of getting a space in a marina (there are not that many anyway) so it was mainly anchoring
. The island is very nice, some very nice placed to visit and hikes to do. Main issue is there is often a swell which comes in from the north due to the Mistral blowing around the top of Corsica
or the south if the Bouche (I think that's what it's called, the gap between Corsica and Sardinia) is playing up producing some particularly strong winds. So rolling at anchor
can be quite testing at times, need to plan the circumnavigation with the weather
But... in May it will all be less crowded so greater chance of getting a place in a marina now and then.