But on Tuesday I stopped by Lordco to see what kinds of automotive goodies they had in stock. I was pleasantly surprised to find some AVS Ventvisors specifically for the Suburban/Yukon XL, Avalanche/Silverado/Sierra family. These ones were also in-channel so I didn't need to worry about sticking anything on the Denali's paint.
In the past, I've always bought Weatherflectors by WeatherTech because I prefer in-channel visors, but I found them a little tricky to install because they were quite brittle. I cracked the ones I installed on the Sequoia (luckily not somewhere visible). These ones by AVS (Lund International) were...
...cheaper by about $20 and by buying them at Lordco I wouldn't need to pay for shipping or drive down to Point Roberts to pick them up.
Installation was quite easy and made easier because these visors don't have the bottom leg (which I found sometimes to obscure the view of the side mirrors). They are held in by tape, but the tape is on the inside and not visible. Even the rear Weatherflectors are held in by tape.
I was able to test them out the next day in the rain and they work great. With just the two front windows rolled down a bit, there was a lot of air flow into the cabin that kept the windshield from fogging up. I have not noticed any increased wind noise from the visors, even at freeway speeds. The only noise I heard was when I encountered crosswinds and even then it wasn't that significant--especially when the stereo is on.
Another nice thing about the in-channel visors is that they don't stick out from the side of the vehicle too much.
The only problem I've encountered with the Ventvisor is not caused by the Ventvisor at all. It comes from the design of the Yukon XL's front windows. The top rear-corner of the glass is curved and it creates a gap that will allow water to come in. I felt a bit of water hit the back of my head while driving on the highway during heavy rain. The fix is easy: I just have to remember to raise the window a bit more.