My photos from the event:

The guys as I approached them after finally getting to the convention, and walking past the insanely long line which had to be people buying tickets for the day (those Early Entry tickets are well worth the price)

Several hours after the first pic (I didn't do much photographing this time) - Law getting to play with the Sniffer as I wore Nick's Proton Pack

Law's found something...
Lawrence :"Jeez, when did you last wash your suit, Andy?"
Andy: "Nick, you said you'd get it washed if I did your shopping chores"
Nick: "Yeah... about that..."
"We're ready to believe you"
Shodanmark, Goosebuster, loly2kn2 and (I'm terribly sorry, I've forgotten your name)

Group shot shortly before we went our separate ways (wish I hadn't had that bloody bag in there, but I suppose a shot with all of us when I have my Proton Pack built will be better.

And me wearing Nick's pack. It was
awesome.
I have to say, certain issues aside it was even better than last year.
Said issues included a severely annoying transport issue where there was no direct train to the center, missing one of the guests who I wanted a autograph from, not being able to get a copy of their book to try get autographed, missing out on Craig Charles who I hadn't known was there and Atari not even really being there at all*.
But... as it happened the disappointment at there not being a copy of the game, and those other issues was wiped out by the attendance of the Ghostbusters.
It was frankly amazing, and even better that I was also able to attend in costume with the Sniffer. It was also a blast getting together as a group for people to take photos of us, and for when we were interviewed for some sort of documentary.
Thanks for the awesome weekend, guys. It was great to see you again and to meet those I hadn't met before.

It was also kinda fun travelling on the trains home, a lot of people reacted positively to the costume, a few parents pointed me out to their children and on the Central Line from Tower Hill Station, I may have convinced a little boy that the Ghostbusters are real because as soon as he saw the logo on my arm he couldn't stop looking at me, and even pointed me out to his mum.
I think I've conqured my self-conciousness for wearing the uniform in public. Possibly partly because compared to some of the things people wore at the convention, it was actually pretty normal.
* They were there, but there was nothing that really stood out at you as "Atari", there were no banners or other obvious merchandise.