Looking to replace my current Samsung Galaxy S4 and was considering a Note 4 or 5 but not sure which one ?

In addition to the phone itself, I want something that gives me "laptop" functionality but is easy to carry around - used to have a 9 inch tablet (until it died) but even that was too big ... ok for the couch but too big to carry around in your pocket 

So I have narrowed it down to a Note but cannot decide between a 4 or 5 ?

Any advice would be greatly appreciated