I am currently using the Plymouth Encore Chunky for my block of the month afghan (we are through block 7 out of 16).
It is absolutely not comparable to any of the lionbrand products. Far superior, IMO. Even though it isn't all natural, it feels nice. yet it isn't scratchy or sheddy to work with. It has a nice flexibility to it, unlike the homespun. My hands don't get tired with it. I have been very happy with it as a choice.
Right now I am using a bamboo needle with it, but my knitpicks option needle in the appropriate size has freed up so I am going to switch back to that.
I am knitting my afghan with 10 1/2's - that seemed to give me the right depth of fabric for the variety of blocks and techniques that we are using. I would think that it would adapt well to the speedsticks.