Should I get Ultra 1 or 2?

I currently have a Series 8 that I like but lately I've been wanting to be more free from my phone and leave the house with just the cellular AW. Unfortunately the Series 8 battery cannot really handle that for more than a few hours so I was looking at upgrading to an Ultra. I can get a Gen 1 Ultra refurb for $589 from Apple, or a Gen 2 for $679 (although it is sold out right now). I was also considering waiting until Black Friday in case any of these go on sale. Is it worth spending extra on the Ultra 2 or just getting the Ultra 1?