Some of the last games released for the Amiga (1996+) did support improved graphics when faster and higher spec CPUs were detected, but there are not many games that did this.

The faster CPU emulation will definitely help with some 3D polygon based games. The First Person Shooter style games like Alien Breed 3D or Gloom will run in higher graphic resolutions with better pixel sizes and much smoother. Also many of the 3D games like Frontier: Elite 2 will also be smoother with faster CPU emulation.

It really depends on the game.

There is also one other big plus point to finally getting 030 and 060 emulation. Most games and a lot of other software originally written for lower spec CPUs (68000 and 68020) often refused to work with a 68040 CPU, but the 030 was much more compatible, and the 060 was very compatible with the anything that worked with the 030, so being able to emulate these two CPUs is better than the 040.