Since all my finished TW2 playthroughs were only with the FCR mod installed (I'll explain why in a bit) all my play styles boiled down to a hybrid build by the end of the game since with FCR all abilities have one level instead of two and that made it easier to get deep in each of the 3 skill trees. But I focused on different stuff in the beginning each time. First I went with alchemy then signs then swordsmanship. Then on other playthroughs I went for swordsmanship first or signs.
Generally I tend to go with sneaky melee types in RPGs if given the choice. So on my first playthrough I'll probably go for swordsmanship while using signs for crowd control mostly but it's not set in stone, it depensd on what skills I find more attractive. I really hope we won't have to get "beginner skills" before investing in the three trees. Never quite understood behind the reasoning of that in TW2, you're Geralt of Rivia, The White Wolf, famous for your deeds and skill, why are you treated like someone that just passed their Trials of Grasses?
I really liked playing TW2 with FCR. I really liked some of the changes especially the XP reward changes with completing quests being the only source of XP (they're doing the same for TW3 which is awesome), the more responsive combat and the skill tree changes (more rewarding, beginner tree already maxed out from the get go). I also liked the fact that blocking didn't take vigor, instead it was based on a stamina system of sorts running in the background, you could only block a limited amount of hits so you couldn't just stand there but neither were you forced to roll 24/7 in order to keep vigor up. And vigor didn't influence sword damage so you use it solely for signs.
Didn't like everything in it though, I get the choice Flash made regarding the more low fantasy theme for the items you get but sadly it made most items very generic, none of them stood out from the others except for the +X to damage or armor. Overall the whole thing was quite well thought out though.
I don't really like the fact that blocking and vigor are yet again linked in TW3. I'd prefer a system similar to FCR.