To know whether the chaps on the ground calling for help are best served by a subsonic or a supersonic aircraft (assuming that both can offer the same weapons, sensors and comms with the troops – which is in itself a very big assumption!) one needs to know a lot of info. How far are they from the aircraft’s operating site? What is the scramble time of the aircraft (from shout to being on heading with any necessary flight refuelling done)? What are the weather limits over the target and at the operating site for both types? What is their endurance over the target and so on.
Which type will best serve the survivability of the aircrew brings in another whole bunch of factors that depend on the sort of enemy they are up against and the enemy’s air defence capabilities and who has air supremacy in the area.
I guess I feel that people who boil the answer to such a complex problem down to a few throw away lines either don’t understand all the issues or are a tad prejudiced. The biggest thing of course is that real men don’t fly subsonic aircraft do they?