The Witcher 3: Wild Hunt's v1.07 patch is a significant one for both current-generation consoles. Weighing in at 7GB, it attacks a wide array of issues that weren't dealt with in previous patches. Unfortunately, it also has a negative side effect.
Eurogamer is reporting that installation of the v1.07 patch has affected framerate for the worst. The PS4 version was seen operating at 25FPS in Novigrad, and the Xbox One version experienced drops up to 8FPS in size when compared to performance in v1.06. These issues affect both outdoor and indoor areas of the game, although the drops are most noticeable when galloping around the game's open environments on a horse.
Complaints are already widespread, yet CD Projekt Red hasn't released a statement regarding the issues. Visiting just about any forum that discusses The Witcher 3 you'll find that a large sum of players are either avoiding installation of v1.07, or are taking a break from the game until the next patch arrives.
Surprisingly, Eurogamer's conclusion states that it recommends installation of the patch due to its "wealth of positive changes". It's a tough call and comes down to how much you value framerate.
To see a list of the fixes that v1.07 includes, go here.