Here is a quick review of some of the strings Quickie makes.
Lucky 7- This was my personal favorite, it held tension the best and still whipped really well. About Toxic speed, but manages tension better IMO. Came in some pretty cool colors to boot.
Quick 13- This string was really, I mean really fast. I think it has a hair or two of nylon in it. Fun to fool around with, but too fast for me to use seriously.