"Low level penetration is hopeless nowadays - radar isn't the only sensor to say you're coming - and as I mentioned, even in WW2 which countermeasures stop cannon shells ?!"
...darkness?
The F-111 performed pretty well in Vietnam ...flying some 4000 sorties between October 1972 and March 1973 with a combat loss rate of 6 (0.15%) lowest of any combat type...which was the time period when the TSR2 would have been in service..