I've been using cyco for several months now and the XL is a really impressive product. First, I must say, watch the pH when using the xl, as it will drop your pH significantly. But, it will thicken up your stems, increase your root mass and just over all make the plants stronger. Make sure your plant is healthy and stable before using this product, as recently I was messing around with it and added it too early in my veg. Lets just say, I really had to work to get it back to where it should have been. All in all, I've been really impressed with the line and how stable it is. I heard they are supposed to be coming out with a root product. I have a friend who tried it and he totally was excited about it. Can't wait for that to get released.