Seem to have a bug with this latest version of the firmware, which I didn't notice with 10007.
Following a power-cycle of both routers, when I roam with my Nexus 5 cellphone the phone seems to roam between the main router and the AIMesh node just fine. However, after about 12 hours if I try again, then the mesh node connects for a moment or two, then I'm kicked off back to the main router, which then kicks me back to the mesh, etc.
I'm not using Roaming Assistant at all. The problem is only temporarily resolved with a fresh power-cycle of both routers. A "soft" reboot doesn't seem to help.
I noticed in the system log that over the twelve hours there were several messages of "link down" with what appeared to be a reduction of link speed from 1000Mbps down to 100 Mbps, or in one case down to 10Mbps. I'm using an Ethernet backbone.