What is the difference? Isolate tends to be a more highly concentrated form of protein and is lower in lactose. On the downside it is perhaps a little higher in cholesterol and usually more expensive. If you would like to know a lot more about whey proteins read this.
Everyone should be taking a whey protein supplement to get the most out of the strength training sessions as the unique properties of whey allow faster recovery and better muscle building and fat burning results. Sounds good. Those body builders were ahead of the curve with this one. Science is only now catching up.