i have never used a hempy, but have really been looking into them as i think they sound like an awesome way to grow.. from all that i've read, it seems like a hempy will surely outperform a straigt soil grow.. i've read that as soon as the roots hit the open area in the bottom of the bucked where the nutes and water combo lie, they really take off.. it kinda sounds like a cheapy version of dwc if that makes sense, and i have seen some really huge grows from dwc.
i was thinking of trying a hempy on one of my next grows, but still haven't made up my mind as i don't have alot of room in my grow area and im not sure how many five gallon buckets i could fit in there..