I really LIKE the idea of packet analysis and some of the stuff he talks about in his book is really cool (or not detectable in logs), but in all practicality it might be too far down in the onion-peeling. ... especially when people are missing some basics.
I think I would have to agree, specifically when relating it back to the original topic of the Target breach. Having SIEM and Flow Analysis in place and using them properly would have likely provided the most "bang for the buck". Packet Inspection is great if you want to get down in the weeds and really pick apart what happened but I think it's less practical from a security/threat detection perspective.