LGW used to be my preferred airport until they started making domestic passengers reclear security when connecting, and also making international arrivals go landside then airside to connect domestically (meaning you couldn't take duty free through anymore).

Since then I've tried to avoid (particularly since T5 opened around the same time, improving the connections hugely at LHR). Making me go through unnecessary security is definitely a way to lose me as a passenger.

Flying domestically ex-LGW, you have so little interaction with staff, it makes no difference if LGW or LHR are better. They might as well be automatons for the brief 2 seconds you interact with them.