Great idea, low profile system with a nice display, simple to use, custom-fit, hooks into mobile devices. Here's my two cents.
Quality of Construction:
I bought a Fuel Band in May. I wore it for about 3 months. I wore it every day, to track my fuel points, which is the system Nike built to measure activity.
The Fuelband fit well. There were problems with the interface, and I had to reset it after a week because the firmware update didn't work right, it wouldn't connect, so I lost all that data. I talked to a service rep and got it fixed. Then I synced it to my iPad and it worked for about 3 weeks, I tracked my workouts, and then the sync stopped working, and it asked me to go to the Nike website and update my account. I did that, and it started working again, until today, and now it appears to have finally given up, just telling me to plug it in over and over, sometimes with a firmware update, sometimes not.
Then there's the LEDs that display everything. They started to burn out after the first month, line by line. I'm down to about 75% of the lines working at this point. Its unreadable now. I was pretty gentle with the thing, so I don't know why they are burning out.
So the quality of my $200 band withstood 3 months of moderate use, and was maintenance heavy throughout that period, and now it is pretty much useless and I'm looking for a new watch. I've done 3 factory resets, the past two haven't done anything and its just giving me the "Error returned from Nike+" when I plug it in to the computer, and the display is giving me the "plug me in to the computer" symbol.
Quality of the Fuel Point system:
The whole idea of this is a minimalist system that tracks activity constantly and passively, without a whole lot of button pressing for the user. Nike put an accelerometer in a rubberized wrist band, told it to record accelerations in any direction, and then puts that data through a formula that spits out Fuel Points, Calories, and Steps. Calories is completely inaccurate. Steps is probably pretty close. Fuel points appear to be based entirely on duration. The longer you are moving, the more points you get, regardless of intensity. So if you run 5 miles in an hour, its worth as much as walking 1 mile around the mall for an hour.
This was proven to me when I did an 8 mile run on a Saturday, and then the next day, I played with my kids for 2 hours on a golf course trail. Vs. the 8 mile run, the kids scored about double points (who knows?), double calories (not true), and double steps (probably true). I was carrying one daughter on my shoulders for a short stretch, but I don't think the FuelBand knew that. A few weekends later, I did a long walk up Mount Whitney. About 22 miles. I got about 3000 calories for that, over the 11 hours it took me, and 11000 fuel points. I'm no scientist, but I'm pretty sure I burned more 3000 calories in 11 hours of effort. I understand it can't take into account elevation, but it recorded 57,000 steps that day, and it gave me very little for it in terms of calories. Even at 10 calories per 100 steps, I should have gotten 5700.
So, Nike, some free advice, which I'm also sending you directly:
-don't sell this as a professional workout system, its not, it isn't accurate enough and doesn't account for things like speed, intensity, elevation change, distance/time, activity type, etc.
-don't sell it to athletes as a performance tracking system, it doesn't track performance in any sort of reliable way, just a single number accelerometer and simple algorithm to put the data through
-I recommend you re-package the existing model as a healthcare device, for people who need to move more each day to maintain some basic level of activity: the sick, the old, the obese, anyone with an overly sedentary lifestyle who just needs to shoot for a number each day to get them off the couch or prevent muscle atrophy
-I recommend you add functionality and re-introduce a performance model, that maintains the low profile/simplicity factor, but includes distance covered (through net acceleration, kind of an inertial nav system, or GPS), workout intensity (possibly through heartrate), and is waterproof. An all-activity performance tracker, that isn't a huge beast of a watch. Nice form factor, now make it live up to the promise of "Nike+ FuelBand tracks your activity through a sport-tested accelerometer. Then translates every move into NikeFuel. Nike+ FuelBand tracks running, walking, dancing, basketball - and dozens of everyday actions. It also syncs up with a motivational web and mobile experience. So put it on and get moving."
-Maybe even hook this new device up to Fitocracy.com, and cross-reference the data with descriptive workout data to calibrate your fuel point system. That might actually get you the innovator/early-adopter demographic you're after, that you can expand into more mainstream audiences.
Hope this helps people on the fence,