Hello, Tips for flying with ants-in-the-pants toddlers at
http://www.totstoo.com/tips
To help you make up your mind, here are some genuine reviews by Tots Too guests who have been to Martinhal...
http://www.totstoo.com/reviews_martinhal
...and to Porto Sani Village (part of the Sani Resort)
http://www.totstoo.com/reviews_porto-sani-village
The weather will be better in Greece at that time of year (meaning warmer swimming pools too), giving Sani the edge, but both places are wonderful!
Tots Too is offering 20% off stays at Porto Sani Village 27 Apr - 25 May, or 10% off for stays 26 May - 23 Sep '12, if you book by the end of Feb.
Early bookers can get 10% off at Martinhal for the time of year you're planning, which also makes for a good saving (book 90 days before arrival).
Or feel free to call the team at Tots Too for personal recomendations for your family... 020 7284 3344