@dan You’re Welcome!
@dev77 Yes there was a major update. Basically it’s a new, completely redeveloped theme designed for Genesis 2.0/HTML5. So yes definitely backup your old files just in case. I wrote some basic info here about what you should do – https://appfinite.com/topic/optimal-1-3-for-genesis-2-0-html5-is-now-available/
Yeah I always recommend separating custom css as well. I personally think it’s much easier to manage.