have it. love it. hate it.
gear display is nice, virtual cadence is nice. operating it from the buttons on the sti shifters is nice.
operating it from the sti shifters is often terrible since i hit the buttons by accident frequently. flight deck gives you the ability to turn on/off the recording of the distance/time etc that you've ridden since the last reset. it only takes one push of the left button to do this. i find that on almost every ride i look down and realize that i've not been recording for the last 5-10 miles. you can't turn this feature off. also the whole system turns itself off after 30 minutes. if you stop that long at a rest stop and forget to turn it back on again, well you lose that info also.