What is the current overall opinion of v5

I spoke too soon, and hopefully I am not again. Right after the previous post I found out about the 5.0.94.0 build. Working without issues or manual exclusions. So far...

 

If it actually port scan attack that is detected by ESS and causing the issues, I'd suggest contacting customer care who should request the firewall log as well as a pcap log with the network communication captured from the moment the issue occurs.
However, we've never had FP on port scan attacks; it's always turned out that a device or specific software were actually scanning for available remote ports which triggered the detection. Probably the other firewalls don't check for attacks within TZ. This is also possible with ESET's firewall by adding TZ to the list of addresses excluded from active protection but is not applied by default as doing so would lower security within your LAN.