Russ you just beat me to the link of the Joel's videos.
I ran into these videos a few months back and had a quick email correspondence with Joel (the guy in the video). Needless to say he was not impressed with the Shorai, but in other videos of his he highly recommends the antigravity batteries (also LiFePo).
I was thinking of investing in Shorai but his reviews stoped me short. I got a Deka instead.
Right now I'm waiting to save up some for an antigravity battery but at the same time I'm holding out for A123 (yes even though bankrupt and selling off portions of the company) to deliver their neophosphate EX cells which solve the cold temp problem!
Once (if) the new EX cells make it to market, LiFePo, I think, will take off in the automotive and powersport battery market.
A direct youtube link of his video is below, his other battery tests are worth watching too.
http://youtu.be/ySNbSZTgplA
Keep in mind this is one guy with his test bench, but his methods seem sound and I think others could probably reproduce his results.