I use KnitPro for all my knitting. I have both the Zing and the Symfonie Wood. I prefer the warmer feel of the wood, but both have the same smoothness that allows the yarn to slip easily across the needle.
The interchangable cords are great too as you can easily change the cord to a longer or shorter length as you work increases or decreases.
I've have had one, unfortunate breakage with the wood, but I can't blame the needle, as you never know, it may have been cracked in an incident after I got it. I will definitely be continuing to use them.
Also, buy from Sconch with confidence. The customer service is amazing and they're always friendly. Thanks Sconch!!