https://community.sophos.com/sophos-xg-firewall/b/blog/posts/sophos-firewall-os-v19-is-now-available
Release Notes: docs.sophos.com/.../index.html
"Old" V18.5 MR3 Thread: https://community.sophos.com/sophos-xg-firewall/b/blog/posts/sophos-firewall-v18-5-mr3-is-now-available
The V19.0 EAP Community: https://community.sophos.com/sophos-xg-firewall/sfos-v19-early-access-program/
About the Upgrade Issues:
See Known Issue List in Release Note
s: 
I have been running V19 on my personal firewall's since the public beta started. Here are my thoughts so far. I also upgraded a cluster of XG230's to test on tomorrow as well.
* Performance-Based Link Selection
Works great until the firewall is under load. When the CPU starts getting above 60-70%, this feature doesn't work as it should. The firewall itself will start inducing latency and jitter on links as it gets loaded down, which give false information to the service responsible for the SD-WAN routing. It seems Sophos does not have any type of CPU prioritization in SFOS to guarantee the firewall will have enough core resources to do what it is supposed to do, even if the CPU is approaching it's max.
* Zero-Impact Transitions
Again, great feature and it seems to work really well, but not when the firewall is under load.
* DPI
No performance improvements on non XGS hardware. It actually increased RAM and CPU utilization slightly on 2 different units. Still no way to disable the DPI engine from looking at inter-vlan traffic and slowing it down, like encrypted SMB that is going across VLAN's at a small site that utilizes the XG as the layer 3 device. Sophos still thinks SMB should have a layer 3 switch for inter-vlan routing, instead of just making a feature to allow the admin to exclude certain traffic from all forms of inspection. The "other guys" allow this. Hopefully Sophos will at some point. It's disappointing because it's nice to know what is flowing between VLAN's, but to do it at true wire speed of let's say 1G, you'd need an XGS 2100 at least, if it's encrypted traffic.
Overall, I do think it's a great build, but I do wish they would close some product gaps a lot sooner than they do (like the logging that still sucks and the lack of a live flow monitor like UTM. Live Connections isn't even CLOSE to UTM's flow monitor).
I will post another update once I have a cluster of XGS devices updated to see how they do. I will probably wait until MR1 though.
Mike
