An interesting post. I liked the link, which I will study carefully. Recently most of my attention has been devoted to watching the FINA World Championships in Kazan.
As far as backstroke technique goes, the main things I think I need to improve are the kick, especially the underwater kick and the holding of water . It seems that a rather straight arm suits me best.
I am hoping to swim in the European Masters Championships in London next year, so I need to add a bit of speed. ;-)