As promised I'm posting about seat availability and not paying to sit together.
We flew out of East Midlands on 28th July to Malaga. We ended up joining the queue a little later than we'd hoped....there were aprox 90 people in front of us. When we checked in I asked about seating and the agent said that seats were allocated the night before, I was perfectly happy with our allocation (a 3 and a 2 including 2 window seats, which is what we like). The family checking in at the next desk over heard the comment about pre allocation and wondered out loud what they'd actually payed for!
So, I still say don't pay and check in early.
Dan
PS just to add, I am 6'3" and pretty long in the leg and I find the 28" perfectly comfortable for a Mediterranean hop!