I'm noticing some....I'm not sure what it is but scrolling across the room is very choppy. Like the framerate isn't keeping up even though V-Sync is on and neither CPU/GPU are stressed. But both steam and the in-game counter stay at 60FPS. Until I run into a boss room where it tanks down to 40FPS or worse. My desktop has a quadcore AMD CPU and I've got a 970GTX so that's....a little concerning to say the least. And this choppiness happens in most medium-to-large rooms. It never happens in small rooms and it's quite distracting from the game itself.
Yes, I'm filling out the mantis reports right now.