Having fired a couple, filmed quite a few, and analysed many others; I concluded that both Firestreak and Red Top were very effective weapons for their era - considering the constraints in design and manufacture (valves and clockwork motors).
The IR detectors and homing head technology probably led the world – I recall reports of an incident in the US involving difficulties in returning a F/S head to the UK.
Air-to-air weapons development advanced rapidly in the post war years, as such F/S & R/T soon appeared to be less capable than competing systems. This might have been true for maximum range or angle-off capability, but there were many mitigating advantages, notably that F/S & R/T worked (high launch success rate), they were accurate, and with their intelligent fusing systems and large warheads ensured a high probability of a ‘kill’.
Jack – splashes ! Firestreak warhead round, Mach 1.3 launch against 48000+ ft target.
I don’t recall any carriage or launch restrictions on Lightning aircraft; both single shot and pairs (ripple) firings were approved throughout the aircraft speed / height / g envelope.
F/S had a sun exclusion angle of about 4 deg, and a very good cloud edge inhibition.
I don’t know about R/T, it used a different sensor.