The TAC escalation process is so inherently broken, that as a customer; I can literally no longer deal with any of it.
We have had several priority one escalations over the past year or so, where it took several hours to arrange a knowledgeable engineer to work on the problem. It has gotten so bad, that several on our team have left our company; one of the main reasons they gave was frustration with dealing with Cisco to troubleshoot. We ended up taking their salaries once they moved on, and scrapped most of the Cisco contract in place; and outsourced it all. It runs much better now. Our new support engineers are ex Cisco TAC (very good engineers), and really have nothing positive to say about their experiences as employees at Cisco. Really sad because Cisco TAC was once the main reason Cisco was great.