Anyone had a fair bit of experience with both? What are your impressions in terms of;
Feature-sets/Reliability/Performance/Compatibility/Support/Availability/VFM etc?
I don't know anything about the Lanner boxes, but I am very happy with the SuperMicro SuperServer E300-8D I am using for OPNsense. It's a very well built little box. I really like that it has IPMI. Very convenient for doing OOB config changes and other tasks.