I'm not really sure if I feel better on Jakafi vs HU; other than when I crashed on HU. The crash cause all blood cells (RBC, WBC, platelets, etc) to fall well below the normal range, lots of fatigue abdominal pain, etc. "Best" thing was I lost about 30 pounds in 30 days (I really did not need to loose the weight, so not a good thing; and when you loose it that fast at least 25+% is actually muscle loss). Many of the associated symptoms associated with ET are progressively worsening, slowly and none to really debilitating - I still walk my dogs 5-8 miles most days and ski in the winters. The biggest argument one might make about making a switch if HU is not an issue is the cost - Jakafi is really high and depending on your insurance, it could be a financial strain. Best thing is to make sure you have the best info and are comfortable with your doc - get a 2nd opinion, they really do not mind. When I did it really only confirmed that my first Dr was a good one.