Decided to add airbags to level out the truck (NOT
to increase payload, that's not what they do).
I looked at Air Lift 5000 and Firestone Ride Rite. I like the beefier components (ie brass fittings, not plastic) of the Firestones. But the biggest reason I chose Firestone has to do with the installation instructions when there is an underbed gooseneck hitch already installed.
The Air Lift requires you to abandon their truck frame U-Bolts and instead drill into the frame for a couple of screws. The Firestone's brackets are designed different and fit into the space between the frame and the underbed hitch casing. Further, the Firestone uses the already existing holes from the removal of the GMC jounce bumper. Looks cleaner, much easier install and stronger to me.
To see the complete install suggest viewing the eTrailer video at this link: Ride Rite Model No. 2528 Install on 2015 GMC/Chev 2500HD with bed hitch
The best got even better when I found that autoanything.com has them onsale for 20% off (code is 20OFF99) with no tax and free shipping. Basically, got them to my door for $369. I'll add a compressor later.