If all other things were equal, I wouldn't choose to do it there. But if I had to, I would not be overly unhappy with the situation.

In particular, I now know that I should get going as soon as the aircraft arrives, in case the transfer point is not open. In addition, I now know about the fast track lane at security (which turned out to be irrelevant for my trip). And I would repeat one constant piece of advice: tell the crew that you're coming back to London with them, so that they know to expect you back. (And of course, make sure you say hello when you are back.)