I played 5s almost exclusively for a good 20 years or so, but in the last 3 or 4 years I've started using 4s again too with one of my bands. For no reason other than I've got a couple of nice 4s and wanted to use them, and the big fat string wasn't seeing any action in that band. At the end of the day it's your money & your choice. Do what's comfortable and what makes you happy. Keep your 5, get a 4 and see how you get on. If you decide to stick with one or the other, that's cool.