I’ve found I defantly have a preference for slippery knitting needles. The more slippery the better. So far my favorite needle has been the aluminum Boyd needles, because they seem to me, to allow the yarn to slide the easiest across the surface, but after a few months of use, (at least for me) the color finish wears off, which causes a bit more resistance when knitting. I’m really not happy about that. My husband has told me he is going to get me some of the nickle plated knitpicks needles for my birthday. (I’m hoping I will have better luck with the nickle plating.)
These particular needles have gotten really good reviews, so I’m pretty excited about that, but in all the reviews I’ve read, I haven’t come across anything about what type of longevity nickle plating has. I’m assuming, or actually hoping it’s better than the Boyd needles. 
If anybody has any experience with nickle plated needles, I would love to hear about it, especially if you have used them for a while. I know they start out slick, but do they actually STAY slick even after heavy long term use?
Edit: I talked to a lady yesterday who uses the Addi turbo needles, (they are made out of the same stuff as the knit picks needles, but are not interchangeable like the knitpicks set is) and she said she loves her knitting needles, and if she could Marry them she would. LOL! She told me she has one pair of Addi needles that are over five years old, and still work great! She says they are soooo much nicer than the Boyd needles and that the nickle plating really does make a difference.