We bought 100 of these for a project and loaded all of them with a custom OpenBSD flashdist image. These are used to establish a VPN tunnel back to a central location using AES-128-CBC, which yields about 14Mbps of throughput using the onboard hardware acceleration.
6 of the 100 CF cards they came with were DOA, but every other component has worked flawlessly during 24/7 operation for several weeks. Netgate handled the returns of the bad CF cards well and in a timely manner.
We purchased these unassembled and created a 128MB image to dd onto each CF card before building to install the OS -- the first one was installed via PXE which worked fine. We don't use the other space on the CF cards, but don't fully trust them after having 6% DOA.
The console settings are a little odd, 38400 8n1, but work fine. I wish Alix would use some more common defaults (9600 8n1 or 115200 8n1). We just set the OS to 38400 8n1 instead of changing the settings on every single machine.