As noted in our review, Divinity II - The Dragon Knight Saga is perhaps lacking in the difficulty department a bit. For those who weren't satisfied even by Hard mode, Larian has thought of you and added a Nightmare difficulty in their latest patch. Do give it a try and let us know how you find it.
Besides that, graphics options previously only available via a hotfix and config file editing are now in the graphics menu, balancing is improved, and a number of fixes are included.
Larian notes if you're running Windows Vista or 7 and are experiencing graphics or resolution issues, you should uncheck the "User interface in desktop resolution" box.
Those who haven't bought the compilation but just the original game and Flames of Vengeance will see their own version of the patch soon. For everyone else, download it at the source.