I just tried this mix this week and it's a great product if you're looking for something low in calories to help curb your appetite and give you energy.
If you're sensitive to artificial sweeteners and/or flavorings, you might not like the taste. Otherwise, I found the taste very smooth with just the right amount of sweetness. I blended the powder with some light soymilk and strawberries and it was very tasty and filling. When I tried it with just water, it wasn't terrible, but it wasn't the best either. Maybe if you add ice and blend it, you'll get a better texture.
So far, I've just had it for breakfast in the mornings before work, so I can't say whether or not you'll experience better performance during a workout. I can say that the mix of vitamins do make me feel refreshed in the morning. I take a multi-vitamin every morning anyway, but I felt a bit of a boost after drinking the protein shake.
I haven't tried many other health shakes, but if you're trying to lose weight (versus build mass), this is probably a good option (and if you're on Weight Watchers like me, you'll appreciate how one scoop is zero points, thanks to the added fiber). I look forward to trying the other flavors soon.