If you haven't gotten the Nexus 6 yet and love having the latest and greatest device, I'd wait for the new Nexus. It's part of the reason I got my Nexus 6 at the time
I got Nexus 6 couple weeks ago to replace my note 4 and couldn't be happier. I got a 32 GB sealed in the box for $450 on craigslist!! That made my decision a no Brainier. I will be selling my note 4 soon to recoup even more than what I paid for the N6.
They are on sale now, so get one, sell your note 4 to help pay for it and then upgrade to the next Nexus when it comes out. We are still at least 5 months out. That's a lot of waiting on note 4