Depends on which features of the phablet you consider most important. If you need/want a better screen and better camera and the price is right for you then absolutely. If you feel you need more processing power and more speed and want to spend the money to get then absolutely. Also depends on your plan and whether you are ready to upgrade and thus what the cost might be. If you were going from contract to edge and could get it for close to the $25 discount (if you have More Everything and 6gb or better plan) then it might be worth. Ultimately It is something that only you can really decide, others can provide their viewpoints and recommendations, or provide information such as the link below comparing the two, but still your decision.
I recently upgraded from the Galaxy S4 to the Note 4 and I personally love the device.