I'd rather think that "public" UFP technology would be more advanced than any old secrets the Vulcans were holding - many species would be divulging their secrets soon after joining, out of self-preservation or out of spite towards their competitors. Also, many UFP members would be young ones, still hungry for advancement, while the Vulcans probably invented everything they deemed worth inventing ages ago. After all, their cousins Romulans apparently came up with nothing much in two thousand years!
So the gap between "primitive by secret Vulcan standards" and "modern" could be even wider than "antiquated by Kirk's standards" and "modern"...
Timo Saloniemi
So the gap between "primitive by secret Vulcan standards" and "modern" could be even wider than "antiquated by Kirk's standards" and "modern"...
Timo Saloniemi