I'm glad you were able to find a solution that is relatively painless for your cat. Towards the end of Jovi's life we were rotating between a whole bunch of different meds and although she still had a good quality of life, it had to be hard on her internally.
If they could talk I think they'd tell us some terrible stories. Cats are rather stoic and don't show their pain or discomfort most often, but they must feel it.