For those of you that enjoy building/putting things together, this is the desk toy for you. It's a lot of fun coming up with new shapes to make, and to show off to your friends.
I have two sets: the black and the silver. I've had them for about 2 months, play with them frequently, and have not had any issues with chipping/color fading.
The price does seem a bit steep, but considering the running price for this type of magnet in general (not just in the toy ball form), it runs about average.
I haven't tried any of the competitors, since I've been happy enough with BuckyBalls to not have to.
BuckyBalls may not be everyone's cup of tea, but if you think they look like fun from the videos (search YouTube for some great demos), you'll probably enjoy them just as much as you think you will.
WORD OF CAUTION: This is obvious, but it still got me. These are magnets, so keep them away from all electronics and cards with magnetic strips! I put mine in my wallet with my cellphone (yeah, dumb, I know). The phone was fine, but it fried the SIM card and I had to get a new one. If you're going to use this as a desk toy, be sure your desk has a good electronics-free area to use.