Pools with Built-In Spas

The new casa currently has a variation of a U-shaped pool and a spa a few feet away.  I don't think the pool is functional for children.  It seems to be a lap pool with two small wings coming out.  I am afraid that the children will hurt themselves because there are many corners and not too much open space.

We are considering enlarging the pool so it has more open space.  If we do that, the pool would run into the spa.  Hopefully it would be a possibility to include the spa in the pool.  I have found several designs where the pool and the spa are together and in my humble opinion look beautiful:

Which is your favorite?

***Images from http://www.hgtv.com/