We asked for one in Jan last year when our eldest daughter was 12 months and to be honest I found it a total waste of time. She was far too old for it, I'm sure they're only really meant for babies up to max 6 months. They're tiny...the width of a seat and are just a little box type affair that they fold open. They don't provide blackets.
The other horrible thing was that on the return journey, the seats that they had allocated for the skycots (they need special attachements against the wall), even though they were bulkhead, had less room than a normal economy seat (it was an older plane as the outward journey, we had lots of legroom), and obviously we didn't have a seat in front, to put our legs under! When it was in place, my poor husband had to spend the flight pinned down in his chair....not fun! Another coulple on the flight had taken an inflatable bath for their baby to sleep in on the floor, but they were told they couldn't do it as it wasn't safe. I personnaly didn't feel the skycot was safe, she kept trying to get out of it, - the sides aren't that high or stable, so I spent the entire night awake watching...just incase!!!!
We returned at the week-end from our latest trip, this time I took one of those travel 'babygrow' sleeping bags, it was great, she could sleep on my husband whilst their belts were still on (The travel type have a slit in the middle and the type I had also had removable sleeves - Jojo maman bebe), so she didn't need to be disturbed at all. While we were there we were able to use it for her to sleep in, and to put her in during the evenings in her stroller, protecting her from the mozzies and letting us go out then placing her in her cot, car seat without disturbing her. Don't know if you'd thought of this, but if not definately worth considering!!! (Although totally off the subject!!!!!!).
Sorry to be negative about the skycots, they may have changed during the last 20 months and you may have a tiny child (my daughter was always on the 50th centile), hopefully you'll find them ok as she'll be much smaller. I'd check-in 3 hours before to make sure you get the roomy bulkhead seats...that's what we were advised.
Have a great trip.