Pros: Keep your feet cooler.
Cons: Some may find styling unusual for tennis shoe.
I was buying another pair of tennis shoes (Adidas Smithsonians) at a sporting goods store that was having a buy one, get one free sale. So, I picked up these as the "free" pair, because I thought the ClimaCool system was worth trying out.
So, what's this ClimaCool thing? Basically, these are tennis shoes with an inordinate amount of vents built in. There are large mesh vents between the Adidas stripes on the sides, perforations in the leather on the forefoot area, and a louvered sort of vent in the arch area of the sole.
Does it work? Well, I tried them out on a fairly mild day (about 75 degrees out). I played tennis for a little over an hour. I normally get pretty sweaty feet, and they often feel hot when I've been playing a while. With these shoes, I did not notice my feet feeling particularly hot. Now, when I got home and took my shoes off, my socks had still gotten sweaty, so the shoes aren't exactly air conditioned. I continued to wear the shoes for some errands (after changing socks). Now that I wasn't playing hard in them, I really noticed that my feet felt cooler, and my socks stayed nice and dry.
How do they play? I am an intermediate tennis player, and have played for years. I think one of the best things about my game is my footwork, and I have worked hard on it. These shoes felt solid and maneuverable to play in. I have two concerns about them that may not be issues for everyone. First, I have a tendency to roll my ankles. I specifically look for shoes that seem stable, with a wide sole. These seemed to be well suited for that, but they caught on the playing surface twice in my first outing with them, almost leading to a twisted ankle. It may be that I just have to get used to them a little more. My second concern is durability. Again, part of my concern is specific to my game -- I drag my toe, and sometimes the side of my trailing foot. These shoes have a synthetic material on the toe, and exposed mid-sole material on the sides and heel. Everything looks fine after a couple uses, but I don't know how it will hold up to that kind of use.
Any other drawbacks? There are two other things I can see that might be good to know for some people. First, these are firm shoes. They are not heavily cushioned, either in the sole/insole or the sides or tongue. (It makes sense since cushioning would retain more heat, I think they minimized it to maximize cooling). If you like tennis shoes that feel like pillows on your feet, these are not for you. Secondly, if you think you might have these on in wet conditions, keep in mind that your feet will get wet. All those ClimaCool holes that are meant to let water vapor and heat out (including holes in the sole) will certainly let water in if you get rained on or step in a puddle.
Overall: I think they are perfectly good tennis shoes, that are probably most worth having if you live in a hot climate. I will probably wear my Smithsonians for more casual play, and when it is not so hot, because they are slightly more comfortable. But, I will definitely wear the ClimaCools when it is hot out, or when I know I will be playing harder.