I ran them for a short bit. I had some of their early ones. Turns out they had a problem with the caps not being made right. They had a bit of a rough texture left inside the cap that would eat the needle bearings, no matter how much grease you shot into the cap. This was a couple of years ago. I have not heard much lately since Omix bought them. All in all they seem like a nice joint. I like the fact you can grease each cap. The needle bearings are captured so they can't spill out during installation which is real nice. Looks like they have a strong alloy with the 8620 gear steel for the cross.
http://4bangerjp.com/forums/index.php/topic,6052.0.htmlYou can see a little info on this thread. ^^
From what I understand the Neapco joints are pretty good. Made in the US. Priced about the same.
I have also run the H20 Proof joints from J.E.Reel. He has them made to his specs. Stronger than the spicer. He has them cryo'ed and they come loaded with the same nasty monkey snot extra stickey grease that the CTM joints come with.
http://www.polyperformance.com/shop/J.E.-Reel-H2O-U-Joint-AX44-p-21315.html Almost double what the Spicers cost.