In reply to Removed User:
I ended up at Vauxwall, as it was neatest to the apartment and I didn't feel like a big hike back after climbing. Initially it seemed really small, sweaty and very congested (more like I had been expecting of London walls I suppose) but after it had quietened down a bit - and the noobs didn't butt in just as you were about to start a problem - it wasn't too bad. The setting was acceptable - I've certainly seem a lot worse.
I even bumped into someone I knew in there and had a decent burger just along the road after it, so a good end to a somewhat iffy beginning.
Thanks again for all the comments and suggestions.