I have a basil survival and I love it.

I have two boys (3 1/2 & almost 2) so I end up carrying all sorts of stuff...toys cups and the like. The keyring on the outside is nice because the front slash pockets are so deep that you can lose a set of keys in them and digging them out once you sit down (as I do most of the time) can be a problem.

The fabric is light enough to be cool in most situations. Bear in mind I live on the NY/PA border. And the fabric is heavy enough to take on quite a bit of wind and not really fly away. Think of wind coming across a few hundred yards of open field. ;)