Yep I had great success with Sannie's Killing Fields in a vertical setup. I grew mini trees (about 5ft high or so). I like it a hell of a lot. Very nice relaxing and uplifting sativa. Always puts me in a good mood. Maybe the best daytime smoke I've ever had.
Attitude is a good place to buy seeds. Sannie only sells direct and is probably the nicest guy in the business, also incredibly good about sending replacements.
My Killing Fields was a nice yielder, I grew from seed so there was some variation, but my most resinous plant was also my heaviest plant. Unbelievable terpene production too. The jars have been empty for a while now and they still smell like it.
I haven't grown Critical Mass, but I think a more sativa leaning pheno from MNS would probably do very very well. I've seen some incredible looking plants too, so there is fire to be found. It ain't just commercial.