I bought and use two vests to say cool. The first is very affordable. I call it my ICE CUBE vest. It is basically a neoprene vest with plastic filled 'ice cube' pockets that use Velcro to attach them to the vest. It appears to be very similar in how it works as compared to the one you purchased but nowhere near as nice in design.
I find I get 30-45 min of cooling depending on the outside temperature (I live is South Florida and daytime temperatures currently run well into the middle 90s). I keep it in the freezer and grab it whenever I go outside and it is in or above the high 80's. When done with it, you put it back in the freezer for next time. After minor modification, I added two additional ice panels to the sides for additional cooling. It is not very heavy and certainly very affordable at $75 from Amazon and it definitely gets the job done for short term usage and is very convenient:http://www.amazon.com/Flexi-Freeze-Ice- ... oling+vest
BUT I doubt you would find it any better than the one you have. How long is your current vest lasting and what is the ambient temperature? How much does the vest actually weigh?
I also use a Veskimo cooling system. I have had some minor issues with it but it does work reasonably well (keeps you cool for more extended periods of time and will easily last 1-1 1/2 hours). You can refill the backpack with additional ice as needed if you bring or have access to ice. It is a more pricey though at over $600. And it does get a bit heavy after a while (I believe it weighs in at about 8 lbs when filled. But, it does get the job done. The battery that powers the pump will last many, many, many hours.http://www.veskimo.com/body-cooling-vest-products.php