Mere bhai, its not about heart sensor! The screen and camera of S5 are way better than S4. Although resolution is the same but S5 screen is the best Amoled screen to date with best color accuracy. The camera is best in the class, read camera shootout review in GSMarena, at times it did beat Lumia1020 as well which is a great achievement. Thirdly it has better battery timings.
So forget heart sensor and see major differences. If you have S4 then obviously you can wait for S6 but if you are new to Galaxy S line then S5 is the best smartphone of the year.
Note3 is good as well but now its outdated in every aspect (screen, camera, performance) and its not everybody's piece of cake due to its size.