It is possible that the 4K Cache is better in terms of those tiny splotches, but please keep in mind that it's still experimental and may sometimes produce unwanted results (we would really appreciate reports :) ).
Hi Maru,
I have been using the 4k cache by default since its release. From my experience, it not only provides more stable GI without any splotches but also results in faster pre-calculation and more rays per second during rendering. It works really well, and in my case, I encountered an issue only once while rendering an animation, where about 3 frames out of a 1500-frame sequence were "broken." I simply re-rendered them, and it turned out fine.
However, it's interesting to note that texture baking is not an option with the 4k cache; it produces a lot of splotches everywhere, especially if the model has explicit normals.
Sorry for going off-topic. I hope that the 4k cache will go final sometime.
If you need some scenes with texture baking where I had really visible problems with 4k cache, then I can provide them to you next week.
Best regards