I was curious on a framerate test in Lumbridge castle between the Java and C++ OSRS clients, and found that there’s a notable difference in the lowest brightness of the game world, with the C++ new client being slightly brighter (screenshots at the bottom; I recommend new Tabs to switch between for comparisons).
There are other subtle differences too like the camera distance (both are at default), the minimap, and fine details on the grass tiles on the outer-edge around the fences. On the top-left-most Gem rocks, the outer-left rock’s shadow loses some gradient and fine details on the shadow on the that are seemingly “smoothed-out” on the C++ client.
I prefer the Java client’s more saturated colors and the harder-red. I’ve played from the Java client at 50 FPS for years and I’m used to it (along with needing no extra features from the C++ client), but I got used to that smooth camera movement with GPU acceleration.
I’m playing from the Java client again currently (Jagex Launcher), and after a few days I haven’t felt the need to switch back to C++. Black colors actually being black and other colors being saturated is nice! You can find my RuneScape hiscores and screenshots here.
Legacy Java Client:
New Official Client (C++):
