I've never totally understood how a slot is a slot is a slot, because the rules don't actually work like that. If you're the only Super aircraft movement in amongst predominantly Medium aircraft, the required wake separation is going to mean you'll consume more than one slot.
As far as I'm aware, there's also legal requirements at some airports for a certain proportion of slots to be used for domestic flights, most notably at Heathrow. No idea if that applies to Gatwick too?
I believe some of the slots at Gatwick are reserved, I believe the slots for Ireland. But I don't think there are quite as many as at Heathrow in the wake of BMI.
I agree with the comment about the slot not being a true slot system with the differences in wake turbulence. I would guess the slot is given on the basis of a certain type of aircraft operating X number of times in the year. I would think a slot for any of the Super Heavy jets is specific and the additional time for the wake to clear behind is built into the cost of the slot.
Fowler: I'm sure they make an impressive sight. I saw the A400m fly over my car on the Brussels ring on the way into Zaventem, escorted by F15s. V impressive!
Richard_B: Was the flight on the 737? Would be interested to know how the flight was. I would imagine that the older travellers might be willing to pay a bit of a premium to travel on a 'proper' airline. Might also be just the time of year; I can't imagine the weather is all that great on the East Coast this time of the year.