Why 2000'?
It is a well-known meteorological phenomenon that all cloud bases start at 2200', which is why we all fly at 2000'
I agree with foxmoth, fly high, see more, hear more. The problem in the South East is London TMA at 2500' minus ground rising to 300' and 1500' Low flying Rule only leaves 700' to fly in. I can't help but feel that if all the London TMA bases were raised by 500' it would help. Also, isn't it time that the zone height boundaries were reviewed? I understand that they were established back in the 1950s, when prop-driven airliners had different descent profiles to todays jets.
Anyone from ATC care to enlighten us?