Has anyone ever used Bishop Wisecarver slides or actuators? I'd like to hear both good and bad about this product

They seem to have some advantages over THK's, etc. Mainly cost.

http://www.bwc.com/html/index.html

Thanks

I USE BISHOP WISECARVER DUAL-V BEARINGS, AND I CAN'T SAY ENOUGH GOOD THINGS ABOUT THEM. THEY ARE THE BEST QUALITY BEARINGS I HAVE EVER USED. I BUILT MY OWN WIRE STRAIGHTENERS AND USE THEM FOR THE BEND ROLLERS. I HAVE LITTERALY RUN THOUSANDS OF MILES OF WIRE THROUGH THEM. AND NEVER WORN ONE OUT.I ESPECIALY LIKE THE FACT THEY ARE A DUAL ROW SET UP, VERY GOOD QUALITY.:)