Both are great. The joins of the cable to the needle, as well as how slick they are are what makes knitting with them pleasurable. Since stitches don't stick or hang up anywhere, the knitter can quickly slide stitches to the end of the needle and knit away.
Knitters in my knitting group have tried the Addis, and most have reported the same thing- they knit faster, with less hand fatigue. Addis range from $9- $20 a pair, and the Inox ones range from $4-10.
Another great needle with a smooth join are Susan Bates ones. Their join is similar to the Addi/Inox, only difference being that Addi/Inox use a nylon material for their cable. The Susan Bates ones I'm talking about have a clear plastic cable. I can only find these needles at JoAnn's crafts. They average in cost from $4-$7.
I still want a pair of the handblown glass knitting needles. They are straights, so I know I'd never use them, but they would be great to look at!
http://www.glass2art.com/needles-1.htmThey start at size 8 and go up to 15.
Simply beautiful!