Currently 4.6.1. Should I install 4.6.4?

Just unboxed my Fire Phone and it's prompting me to install update 4.6.4.
Should I do this? I see a lot of talk about downgrading 4.6.4 to 4.6.3, so I'm not sure if 4.6.4 is going to hinder me later when I try to root or install CM.

Thanks!
mike