I can't comment on specific timeframes for R80.10, though the Release Plan SK says "several months": Check Point Releases Plan
There's a lot of other benefits beyond just the unified policy in R80, even with R7x gateways.
A couple of my personal favorites include:
- Unified SmartDashboard + SmartLog + SmartEvent
- SmartConsole also has several usability enhancements over R77.x SmartDashboard
- A robust CLI for making bulk configuration changes
I wrote a more lengthy piece about R80 management here: http://phoneboy.org/2016/04/03/why-check-point-security-management-is-still-the-gold-standard/