I wasn't able to find any threads concerning a direct comparison between these pedals? With all the great Black Friday deals online, currently, I considered upgrading to a set of one of these?

Weight-wise, they are spec'd as follows:
Dura-Ace 7900: 248 grams per pair
Ultegra 6700C: 258 grams per pair

Reviews on both are excellent! Is there any reason to spend the extra cash on the Dura-Ace? I'm currently riding Shimano 5700 pedals. Are the Q-factors similar to my current pedals?

Thanks, Scott

he Ultegra should have the same Q factor as your 105 pedal's while I believe the Dura Ace are something like ~1mm or so more narrow. My personal experience seems to back this up as I felt the need to move my cleat a bit out on the Dura Ace to get the same knee/leg tracking.

I would say unless you really want the narrowest Q factor possible or have all Dura Ace on your bike otherwise, don't both with that much extra for a few grams.

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Looks like I made a new 90 Proof friend

But bearings in Dura Ace are superior and that's important for pair of pedals.

Dura ace have a center needle bearing along with the standard two rows of ball bearings, so technically it's stiffer. No, I've never measured or noticed pedal body flex on my ultegra pedals. I tried measuring the pedal stance difference between the two, it was VERY hard to tell.
Oh, one surprising difference is that, according to Shimano documents, the dura ace carbon pedal is the only one in their lineup in which the top wear plate is NOT replaceable. Odd.

Dimensionally, the q-factors are almost identical. I couldn't tell visually when I compared them by eye.

However, the stack height of the Ultegra is higher. ~2mm or so higher. Not much but noticeable if you do a blind test and swap between them.

The seal and bearing quality of the DA ones are far superior. Its just buttery smooth out of the box. The Ultegra is a little draggy out of the box. And as mentioned, the bearing arrangement on the DA is way better for long term use.