Hi Dick,
I have not tried them, but I do not like the looks of the crimps to terminate the lines. I have only bought 1 set of steel lines from them and one of the crimps failed during flight. Anyway I think I saw someone sport-flying with a set of those lines last day or so of Brodak's this year.
Combat has recently gotten synthetic lines approved for use, generic name is GSUMP. I think that is gel-spun ultra-high molecular polyethylene. I forget the trade names but you can get it from Cabela's and places like that. Probably more recent real-world testing than the kevlar lines.
-Chris