Browsed around a few of the walk-up buildings thanks to the helpful thread on this site and stumbled across Sara on the top floor of the Peter Street building.
She's South American and probably in her 40s. Slim body, fake tits and a pretty MILF face, in some nice lingerie. Overall I found her attractive and went for it. Paid £40+2 for OW + missionary sex.
Didn't go in expecting anything spectacular, but it was a solid punt for the price. She was as enthusiastic as I could have realistically hoped for, with a decent amount of eye contact. Finished in the bag, chatted briefly while getting dressed and headed out.
Not in a hurry to return, but if I felt like another walk-up punt it seems like she's a safe bet. If I do return I might ask for a longer session.