Nice boat, great location
I took my family to Dubrovnik in this Lagoon 42, and was not disappointed. Initially I had some concerns because this was an older boat (2019) than we'd taken on previous cruises, but my worries were unfounded; it was still in great condition with only very minor clues to her age.
The staff at the base were very helpful, although clearly very busy turning around many boats on the same day. The boat was available to us an hour or so ahead of the scheduled time, although of course we did have to wait around for a few hours after checking out of our hotels.
We self-provisioned, and found that there were quite adequate markets nearby to allow us to do that. We also eat at some restaurants in the area (which generally seems to allow free overnight use of their moorings, which is nice).
The weather in late September was generally good; mostly warm with very few clouds. That said, we had one day that had thunderstorms and force 6 winds that brought swells up to about 6 feet. The boat handled this easily of course, simply by following the reefing guidance in the manual.
The boat checkout was briefer than expected, but that might have been in part that I mentioned having taken the same model boat for a charter so the briefer might have felt it unnecessary to go into minute detail.
One thing that I did miss was a skipper's briefing. In other locations I've been given a briefing consisting of an hour or two of what I'd call "local knowledge". When I queried this I was simply told "you're the skipper". Well, that's true, of course, but I believe a smart skipper seeks out local knowledge to augment what's in the pilot guides and charts. I'd like to see this added to the base's offerings.
The region is beautiful, of course, and the many islands have coves offering shelter from different directions. There are also cliffs, caves, and of course rocks. Get a cruising guide and study it in advance, and pay attention to the charts!