I've grown the GHS Jack. The high is very pleasant and speedy, but the yield is terrible. Very small bushy plants, but very frosty. Very light smell, but it is pretty cool. It will smell like cheese, and then you turn your head and it smells like a haze and at a distance it is a bit floral.
Overall, for someone looking for a Jack, I most definitely not recommend it. For someone looking for some good trippy personal stash, maybe. The yield is very low for a decent product, though from what I've seen of other Jack's it is a poor representation of Jack Herer. Although it does not fit my tastes, almost everyone else who tries mine loves it. It is very psychoactive. Lots of tracers, sensory enhancement, but it comes with loads of paranoia, lol. It is a lot of fun though, very heady, giggly, and fun