A tale of two terminals
It’s well known that I’m no fan of Heathrow Terminal 5; the arrivals experience and flight transfer process seems unnecessarily awful, especially the security screening experience.

On my most recent business trip to the UK I flew United in and out of Terminal 2, and it was a much more relaxed experience. Certainly there’s a good deal of walking involved, but the spaces seem less claustrophobic than in Terminal 5.
EU passport holders can take advantage of the automated entry gates that scan your passport and use face recognition to compare you to the picture on file – it’s essentially the same system as GOES in the USA, but you don’t have to pay for the privilege. Through immigration with barely a break in your step, the slowest part then becomes the wait for other passengers to retrieve their bags from the carousel. Terminal 2 carousels are very quiet, but rather small. Conveyers are controlled by sensors that watch for a gap on the belt and then scoot a bag out to fill it – but if the delivery carousel is already full of bags whose owners are standing in immigration then there’s nowhere for your bag to go!
The terminal as a whole benefits from an extensive recent overhaul, and public spaces are pleasant. Upon checking in for the return flight security went very quickly, and seemed less cramped than the equivalent process at T5. While there’s still the same emphasis on retail space, there seems to be more seating available for travelers – or it could just be that Friday morning is a very quiet time to travel! Regardless, T2 feels a nicer choice than T5.