I was at the show last year - my first and to date only show. I enjoyed it a lot: there was a good mix of people to speak with and things to look at. I'm going to go again this year, if I possibly can. For me, it was quite intense: I can't imagine a two-day show - and with London prices as they are, I imagine it would be unaffordable.
I have one piece of advice that has not yet been made in this thread: take a loupe, ideally with a built-in LED, and use it to carefully inspect whatever you're thinking of buying. One of the purchases I made last year had a flaw that I didn't notice when I bought it, but which would have been evident under a loupe (if I had only taken one with me). I would probably have bought it anyway, but it was an unpleasant surprise later.
Also, I second the sage advice of others; two points in particular.
Cash. this is excellent for the show-goer - you has a budget and you sticks to it. And you makes life easier for those vendors what prefers cash.
Yes, you can go to the cash dispenser a few minutes' walk away if you're a bit short, but a) you can budget that extra cash for unplanned finds, b ) there is a limit to how much cash you can take out in a day, and c) the walk to the machine can act as a good moment to cool down, if that sort of thing is useful to you.
Luggage. I would recommend taking nothing larger than a slim shoulder-bag.
I went last year with a fairly small rucksack. It was just too big: I found myself knocking into people whenever I turned anywhere. I won't repeat that mistake.
Edited to get rid of the auto-formatting that turns a grammatically-correct "b )" into an emoticon.
Edited by stephanos, 20 August 2016 - 17:58.