The Highs:
The panels.
Particularly
i. Everyone's A Critic with Niall Harrison and Paul Raven, Reviews Editors both -of Strange Horizons and Interzone respectively, Tony Lee and Andrew Drucker, reviewer and blogger respectively, and an intelligent and courteous audience.
ii. The UK SF Short Fiction Scene, with Harrison (again), Jetse de Vries, one of the Fiction Editors at Interzone, and the irrepressible John Meaney. Terrific fun.
iii. Also (as one of the audience) Terraforming Venus with Professor Nik Whitehead of the University of Akureyri lecturing, and delivering an intelligent, articulate and above all fun look at the subject.
And meeting lots of people I 'know' online in the flesh for the first time, plus a few idols of my youth.
The Lows:
Not many, actually.
One of them was that I stupidly double-booked myself, but with the aid of the con volunteers (who did a tremendous job) we managed to salvage the situation. So to all panel attendees, check, double-check and check again your timings.
The other was that I ended up doing a book-signing session opposite panels with the GoHs in, and nobody -but nobody- came. Such are the perils of signing sessions. To any other new authors, I'd say "don't do it until you have a fairly high profile."
But the lows were far outweighed by the highs. I can hardly wait for Bradford 09.