As mentioned in another post, I bought the fogs mentioned above, and I like the color, but I'm not 100% satisfied with the brightness/output. I did some searching for the PSX26W bulbs and found these which claim they are 50w vs the 30w of the ones I already purchased. They definitely have more LEDs (16 vs 6).
http://www.amazon.com/dp/B00OVQWX3G/
In fact, they are only $5.02 per bulb more (they come 2 in a pack, whereby the ones above are single bulbs).
I'm considering getting a set to try them out, but I'm somewhat concerned about heat buildup also. I know guys had issues on the last gen Yukons and actually had deformation of the housing using higher wattage bulbs. The fog light area is not as small as the last gen Yukon so it might not be an issue. I also sent a message to Dante (HIDGuy) to ask him if he offers a higher output bulb than the 30w that I bought. I plan to ask him about the heat buildup also. I'll probably wait to hear from him before trying.