The T21's were, in fact hopelessly underarmed show-ponys that proved to be death traps during the Falklands campaign. These Vospers built ships were ideal as export frigates and for low level patrol duties but no use at all in a shooting war, completely vulnerable to air attack.
Got to agree with the structural defects that were highlighted during the Falklands conflict. Plenty of overtime became available for the Devonport dockies to reinforce the remaining T21 fleet with hull ribbing and other strengthing techniques shortly afterwards. They still operate today on foreign shores. There was a comraderie on these ships second to none during their RN tenure (the Type 21 Club) not evident elsewhere in the fleet then, and to this day not repeated, to my knowledge.