My first impression was that they didn't clip in well in the snow, and if you graze a rock or stump with them there's a good chance they'll be rendered utterly useless. That's kind of a bad feature in a mountain bike pedal, really. But if you are willing to run them in full Nubbins trim, you can save a lot of weight over conventional pedals, and when you're a weight weenie, nothing beats that. You can never be too rich, or too thin. And all that comes at a great, sub $75 price.
The New Crank Brothers Candy Nubbins Pedal

They've really taken pedal innovation to "11" with the new Candy Nubbins. They shaved a ton of weight - nearly the whole weight of the old Candy C pedal system - and they narrowed the Q factor by over two inches per side. They accomplished this by boldly removing the platform and clipless mechanism entirely.
Yep, they went where Shimano and Time are afraid to go: they just sheared off the business end of the old style pedals, resulting in a whole new paradigm for mountain bike pedaling.
Shaving Weight Off Your Pedals
The Crank Brothers Way
The Crank Brothers Way

Sure, there are some drawbacks to this new pedal system. But what product doesn't have some drawbacks? In the case of the Candy Nubbins, it's a little hard to put down full power when you go for a max effort to get up a steep hill. It's also a bit difficult to clip in at times, but I'm sure I'll get the hang of it after a while. The only other complaint that I have, is that it's nasty doing a one legged pedaling drill up Lewis & Clark Trail and then down the Log Trail to get back to the truck.
Crank Brothers should be applauded for the innovative method used to spontaneously upgrade pedals to the Candy Nubbins system. Mine spontaneously upgraded from a Candy C to a Candy Nubbins on the middle of the little kicker at the end of Lewis & Clark, when I stood up to crank the bike over that steep little hill with one of the brief, all-out efforts that are so common and necessary in single speed mountain biking. Imagine my surprise when I found myself with a whole new pedal system above my foot. It would have been under my foot but I was upside down at the time, trying not to cry. My friends were thrilled by the spontaneous upgrade, judging by their laughter and the smiles on their faces, and really, isn't laughing and having fun what mountain biking is supposed to be about?
Candy C-to-Candy Nubbins Conversion Kit:
Just Add a 1600 Watt Effort
Just Add a 1600 Watt Effort

Crank Brothers should be commended for producing a product that brings so much joy to my riding buddies. Personally, I could give a fuck what they think and will probably get a pair of pedals less likely to have two catastrophic failures in a three month period, and will likely go back to some old Shimano SPDs I have lying around until I can afford to upgrade the fleet to Time ATACs.
The bottom line is that the Crank Brothers Candy Nubbins, Candy Cs, or any pedal in the Candy line is just the ticket if you're into highly entertaining equipment failures. They make the perfect gift, really, for some buddy you like, but also like to play mean practical jokes on. My experiences have been consistent; at everything other than cyclocross use (where I do endorse eggbeaters and will use my Candy SLs), these pedals will let you down, and they won't let you down lightly. They are damned good at what they do, and if you're into that sort of thing, I higly recommend them.* † ‡ **
* Not recommended for use by clydesdales, on hills, for "all mountain" or "freeride" or "XC" or "epic" or "endurance" or "trail riding" or "commuting" applications, or for persons above recommended weight limit of 87 pounds.
† All warranties void if the above described mountain biking pedals are used for mountain biking purposes.
‡ Above bicycle pedals not intended for bicycling use.
** No warranties, express or implicit. Use of Crank Brothers Candy Nubbins Pedals™ constitutes waiver of all legal recourse against Crank Brothers Inc.
Ps. Happy New Years, people. I entered the year with a busted back, and am leaving it with a busted pedal. Let's have a little more fun on this next lap around the sun, m'kay?