Good news here as well. We're running two firewalls (at two different locations) with 5.011 and the major problems seem to have disappeared. One thing still not working correctly, however, is the viewing of internal websites using an externally resolved IP address -- that still results in a proxy error. For example, if you run a web server on your internal network and have a DNAT rule to permit external access using the IP address of the external interface, and you try to access this website from INSIDE the network using the public URL, it fails every time. This didn't occur in v4, so this is some sort of proxy issue. It's been reported to Astaro, guess the fix didn't make this up2date.
After I updated from 5.010 to 5.011. Astaro displays some wrong IPs in "Licensing > Licensed users (IPs)". Before the update it displayed IPs, like "192.168.1.2, 192.168.1.3, 192.168.1.4" and so on. Now it displays IPs from some of the websites I visit and my DNS server.