Thought I'd share this from the 4.8 release notes. Glad I did not upgrade to 4.7.3. Guess that's why they are called ED?
Note To upgrade from Cisco NAC Appliance Release 4.1(8) or earlier to Release 4.8, you must first upgrade your system to Release 4.6(1), 4.7(0), 4.7(1). or 4.7(2) and then upgrade to Release 4.8. Note You cannot upgrade your Cisco NAC Appliance deployment from maintenance Release 4.7(3) to Release 4.8 directly. If you have installed or upgraded your systems to Release 4.7(3), you must first downgrade your appliances to Release 4.7(2) or earlier, and then upgrade to Release 4.8. Refer to caveat CSCtj02066, page 55 for more information.
