Just finished chapter 4. The game gives you option to start any chapter you want so old saves are not required (if you remember the plot), there's also a build-in gallery unlocker. Good awareness on the devs part.
As for the update itself. Well, the change in writing after the departure of Asmodeus is noticeable, and it's not a change for the better unfortunately. Almost none of the teasers released a while ago were used, so i guess you can say that Suzinak has decided to start from scratch. I don't want to be too negative, or spoil too much, but I'd only say that there's noticeable discontinuity of thought between chapters 3 and 4, and I wished things would escalate in a different manner but oh well, an update is an update. Glad too see this alive and kicking.