I think that the copound is better for kids as most compounds have a play ground fro kid and a gym also it might have a swimming pool. put with a 21 months old kid you will need to add things like stair gates etc for the saftey of your kids, also cleaning is harder in a villa than a flat. anyway, there is a good british nursery in al waab area and a near by english school also, so this can be an added advantage.
if you need to ask anyfurther questions please don'e hesitate to ask.