Results of testing this RC:
Nexus 5's x2 and one Moto XT926: All working well in Wi-fi infrastructure and portable wifi hotspot mode.
However, one Moto XT701 (original Droid / Milestone class) does not work in infrastructure mode. If services are enabled in this mode, not only does Serval not find any peers, all other LAN and WAN connections fail for all apps. The only time the XT701 finds peers if it creates the portable hotspot, and other devices connect to the hotspot that the XT701 creates.
Mesh networking does not work at all on the XT926. It claims to not find a suitable profile.