Ok to chime in I use the stuff and it works. My first grows were decent without them yes. But I've seen more weight, and dankness using them. My grows are so small I just buy small amounts (like 250ml) bottles. According to the small amounts used at specific stages of growth....I get several uses with a one or two plant setup. Heres the rundown on what I have used:
Bud Candy- frosted things up like never before, but left a slight synthetic taste I didnt like.
Botanicaire Sweet Raw- using this now instead of bud candy. Works great as a carb/sugar and imparts no taste. I like the results better than unsulphured molasses.
Big Bud- swells them up fat, I use liquid form every grow. This is probably one I wont do without. I see what happens within a week of adding this, compared to adding no such product.
Overdrive- The jury is still out on this one. Seems to keep things green and healthy. Dont see any huge difference in flowers or yield. It does seem to keep things going and I dont see any fading or yellowing anymore in the later stages of flower. Things stay green to the bitter end. You could do without and save a buck.
Bud Ignitor- bought a teeny bottle of the stuff to try out more or less. Used during the first weeks of flower. I did get a shit load of budsites all the way down to the dirt. Hard to compare this to how much youd get without it. It did seem to jumpstart flowering opposed to the usual slow 2 week slow onset. This is one to experiment with if you have a few extra bucks, but I will likely not buy more.