I purchased the Islander, flew it a couple of times and now it's in the hangar, waiting for an update from Blackbox.
IMHO, the release version 1.0.0 is not up to par with a modded default aircraft. For example, it doesn't have a working transponder, the fuel capacity is off by at least 10 gal, there's low-res text in the cockpit (something I really don't like), and I believe mixture doesn't behave realistically (fuel consumption at different mixture settings).
I was told that Blackbox tends to release early, but will provide improvements and fixes over time. So right now I'm waiting for that.