SDN != Reactive OpenFlow
Agreed Rob. We've known that reactive flow control is a bad idea since long before SDN controllers were invented. Anyone remember Ipsilon Networks?
It's also worth remembering that SDN isn't just about OpenFlow (reactive or proactive). OpenDaylight, for example, also supports OF-Config, OVSDB, NETCONF/YANG, LISP, BGP, BMP, PCE-P, CAPWAP, OPFLEX, SXP, SNMP, USC (whatever that is), SNBI, HTTP, CoAP, LACP and PCMM/COPS. So expecting it to be the fastest reactive OpenFlow controller in the world is a bit like expecting your swiss army knife to be a better saw than your hacksaw. The real value in "SDN" (IMHO) is in writing apps that use multiple southbound protocols (e.g. learn topology from BGP-LS and program paths using PCE-P).