We started using it when we were first building a growing system based on the articles of a couple key HT authors. It was highly reccomended by Kyle Kushman who, at least then, was imo the best HT author when it came to soil growing techniques. It definately helps but you need to have everything else just right to notice a difference. For example, giving ST to a nutrient deficient plant won't help it at all afaik but it will give an extra boost to an already healthy plant. You also have to measure it out just right. In my experience, too little does absolutely nothing and too much burns. A little experimenting will tell you exactly how many drops per gallon your particular plants can handle. I ended up deciding that it wasn't worth using in veg since we have plenty of time for vegging and so don't need to spend more to speed the process up. We still use it during the second half of flowering to help the plants squeeze out that little bit of extra bud.
