If I were you I'd make a little list of the features I use and the ones I absolutely need, and maybe the ones I would like to have. Then I would take a look through the different ROMs for our phone (they're not that many to be honest) and try out the promising ones. If you don't have the time, post the list here and we'd be able to help you out more easily.
Personally, I'm still switching ROMs around on my phone. Compatibility with a good kernel is a must for me (I use nebula). My musts are a black/dark UI toggle, lockscreen shortcuts, customizable quick settings, notifications and recent apps menu + statusbar traffic monitor. Things that I could otherwise do using Xposed Framework such as custom animations, progress bars etc. are just bonuses. Those things are found in pretty much every ROM so all that remains is a question of finding the lightest and most stable one.
Currently I've got my money on Dirty Unicorns - even for an early, unofficial build, it's pretty stable while offering everything I need. It's smooth and responsive, plus it's feature-rich - it offers pretty much what everybody else also has and allowed me to easily experiment with features I hadn't used before. This helped me find out what I want and what I don't want in a custom ROM.