Am I too late? Anyway; I think Sinking Island is a much better game than SF2. Although a bit flawed and unpolished, Benoit Sokal has in Sinking Island found the foundation for how a whodunnit as an adventure game should be made (take note and learn AWE Games or whatever the developer of those three recent Agatha Christie games is called).
I know some people regard SF2 as a good game. I don't. It borders on being crap but can maybe be called mediocre on a good day. It can't compare to either Culpa Innata or The Longest Journey. IMO I should add.
Edit: But the first SF is quite ok.