Great choice! Maybe check out your stock and unrooted Red (lovely) Nexus 5 a week, and then decide of you think it's necessary to root it.
If you decide to, I recommend flashing Franco Kernel for better battery life (especially in stand by) and enabling ART for a better performance. (You won't be able to use Xposed with ART)
You won't be disappointed, enjoy!
Verstuurd van mijn Nexus 5