FWIW AC Unity is one of the best looking PC games I have ever played. It's buggy and prone to stuttering, but I have managed to get my game looking great and 90% stutter free by turning off SLI and changing some ingame settings and in Nvidia control panel. It's just as buggy on consoles, I do not think the PC version is deliberately toned down. I am fully aware of Ubisofts bad reputation, and for the most part I agree. But I use my own findings on a game by game basis, and to me Unity is a better PC port than most games. It detects my DS4 as soon as I plug it in (a little message pops up) without me having to restart the game, I don't have any other games that do this. It also has full support for 21:9 and multimonitor, again, very few games have this. And the lighting engine in this game is just phenomenal at times. If they could fix the graphical bugs and performance that plagues all platforms, it would be even better.
I will definitely be playing FC4. Loved FC2 and FC3. Not sure what I think of the location on this one, looks like there will be a lack of wide open places and instead replaced with a lot of verticality. I'll wait and see though.