Lots of people have used this and tend to like it a lot... but if you're going to be growing autoflowers, you'd be better off with something like ProMixHP that doesn't have any nutes in it - a lot of amended soils are just too rich for their finicky taste so with the ProMix, YOU get to decide what and how much and when... Photoperiods do very well in it but will need additional nutes within a few weeks...
Good luck!