I absolutely love the GRID + Clique combination. It has made me a faster, more efficient healer from the days where I only used the X-pearl frames to do my raid healing. The amount of information that I can receive in such a small area is what does it for me and I can customize that information into areas that I prefer it to be in.
Only using healbot for a short period of time I cannot comment on it fully. It did seems to have it advantages but I did not like the layout of it and since switching to GRID I have never looked back.
If you are considering use one or the other I would say allow yourself time to get familiar with both of them and go with the option that you feel suits your style.