You may regret getting me started on this, fairy!
Yes, our 2 yo was v happy for a week on Oceana. Once they are 2, they can be left in the children's play room (3 rooms for different age groups).
We didn't leave ours in for a long time, but when he did go, he was very happy. They have fully-planned days, loads of different activities - treasure hunts, sticking, baking, magic shows etc. The staff are absolutely LOVELY (been on 2, Aurora and Oceana).
One or two of the pools will be available for children to use (though they are quite small) and they have to be toilet-trained or wearing swim nappy).
We took ours to the children's tea at 5.15 every day. There was everything imaginable, and it was all bedecked with high chairs.
Then we left them in the clubs, whilst we had a grown-up dinner... bliss!
We like cities with LOs, because we can find so much to do with them.
Any more questions? Bring 'em on!