v19.0 upgrade risks

We did an upgrade from 18.5 MR3 to 19.0 last week. Nothing broke, all Client-VPN and site-to-site VPN are working as before.

I would recommend doing a configuration backup of the firewall system before any upgrade, though.

If you're upgrading from 18.5.2 MR2 and performing antispam filtering be aware that the antispam engine has been upgraded to SASI and the detection rates are truly abysmal. Wait for 19.0.1 MR1 and hope Sophos have fixed the detection rates. (NC-90702) is supposedly the fix for this.

We have done the update with no loss of functions or errors 

ended up upgrading with no problems

done the upgrade with no apparent problems

I have heard from issues with SFP+ modules in combination of LACP trunks (HP and Cisco)

Probably effects DAC and Fiber Cables (with original transceivers). I was told that 10 GBit Copper Cables are NOT effected. 

Did anybody notice problems with IPSec Tunnels (Site-by-Site; Tunnel Mode)

I have an update from 18.5 MR3 to 19.0. After that the LACP connection with SFP+ doesn't work anymore with my Dell S4048 switcht. I'm also waiting for an answer from support.

check for Auto Negotiation. Set it, if not set. 

Auto Negotiation is set.
LACP link with Firmware 18.5 MR3 works well.

You could try to disable it and check, if the Links are online or not.