we wants to use 802.1x and MAC Auth for authentication of the end-systems. Automatic VLAN configuration via RADIUS VSAs during authentication process is a very important additional value for us (XOS - Auth - Campus Mode). Finally we wants using Spanning Tree at the edge ports (to prevent network loops)!
Unfortunately Authentication + Campus Mode + STP is with current XOS not possible!
Current legacy Enterasys devices support that without problems.