Coincidentally, I'm playing that at the moment - I'm enjoying the plot more than normal, seems like he's actually struggling with some moral choices and trying to do the right thing rather than just being set off on a path and ploughing along it indiscriminately killing, though I'm ready for a change of scenery. I think just because the world may actually be too big for me now. Navigating the ship though all those narrow straits make the naval battles and fort capturing a bit awkward and too many separate places to drop anchor means I'm finding it a very disjointed experience. All the separate bits are good though like the cave exploring and even the viewpoints are often not just climb straight up the nearest tower and require a little route planning.
Haven't played unity and I know it has technical problems, but I'm hoping they've used it as a chance to refocus (and dare I say give it a bit of a reboot). One thing I've found a bit weird is that the "back" menu button is also the main interact button so I'm often backing my way out of a menu only to jump straight back into it. I don't know if that's because I'm on 360 when I usually play them on PS3, but another side effect of that is I do not cope well with wild animal attacks as it's not just not the PS3 controller I'm used to for this series, but also the letters are the opposite way around to a Nintendo controller which is the other one I'm used to. That's only a small niggle though and I think the series remains a favourite.