Hi Nicola,1/2 - I have just bought one of these and been testing the captive portal functionality.  These APs are all independent, so you can have one configured with the captive portal feature, and the other two just using, for example, WPA2 authent...

Works for me too - Although I'm not sure even a 2651 is going to provide 100Mbps fdx throughput - it's a router not a switch. Anyone know about this?