I'm pretty sure if you want to improve your knitting productivity that you should NOT use Noro. The silk garden is lovely but it brings out my OCD yanking out all that vegetable matter.
The lever knitting definitely makes one by one ribbing fly. I'm going to run a time trial tonight to compare the speed of my lever knitting versus good old continental.
Felicia of Sweet Georgia has a really great post here describing the Yarnharlot's class on Lever Knitting (aka "Irish Cottage Knitting")
The main issue I've had has been that while trying to anchor the working needle under my right armpit, the needle keeps sliding around. Aside from not wearing fleece (which enhances the slide factor!), I learned from another Raveler to tuck a kitchen towel under your arm to prevent the sliding around. Interesting.
About a year ago, I took the "Knitting for SPEED and EFFICIENCY" class taught by the Yarn Harlot at A Verb For Keeping Warm. Great class and interesting technique.
I practice on some garter and then started on this one by one ribbed scarf. It's true that purling goes pretty quickly with this method. It took me a couple nights of practice to get the tensioning right. Having trouble keeping the working needle tucked under my arm--it slides around. Also, having trouble keeping my right hand braced against the working needle.