From my own experience with Roxy, I wouldn't say she necessarily has it worse some days than others. But, she shakes more when she's excited, scared, focused, etc. When she's relaxed she can make more deliberate movements so she can walk/move better, while excitement will often cause her to...
CH is not a "disease", and it's certainly not a condition that progresses over time. If anything, most CH cats get "better" as they get older because their muscles get stronger and they learn to compensate. Many figure out how to do everything "normal" cats can do, just in their own time in...