I've seen a few TS escorts when I occasionally get the urge (which is rare, and always takes me by surprise as 99% of the time I am strictly girls-only, but there you go). I've used Yummy Asian, where I can recommend:
Valentine (Bayswater):
External Link/Members Only - VERY female, you'd never know she was a TS if you saw her in the street. Great service, lots of kissing, DT blowjob, really friendly despite patchy English.
Riko (Earl's Court):
External Link/Members Only - a notch down from Valentine in terms of looks (still very female though - but must be 6 foot tall, which for some reason makes her more masculine in appearance) - but again, great service (especially DFK, which was pretty continuous throughout the punt), excellent English, and very chatty.
I've seen a couple of others who are not recommended. Lauren, near Liverpool Street/Bishopsgate (
External Link/Members Only or
External Link/Members Only) was feminine looking (the photos in her gallery are genuine and un-photoshopped) but she literally walked into the room, lay on the bed on her back, and did NOTHING AT ALL. Just lay there. And the other one, near Bayswater - my first TS experience - who was enthusiastic and friendly, but unfortunately looked like a bloke in a wig. I can't find her profile now - it was a few years ago so I guess she's retired.