Sorry, I should have at least responded, so that you know that we are actually here and reading.
The previous owner of my new-to-me 2007 Yukon XL Denali had a passive aftermarket suspension on it. I was not happy with it, and the shocks showed signs of leakage. I can't remember the specific brand, but it wasn't one of the better quality brands of aftermarket shocks.
I changed back to OEM GM parts on my suspension, and the ride was much better. Since then, I use only GM parts on my suspension, except for the sway bars (Hellwig). They are pricey, but you can get much more reasonable pricing with online GM parts retailers.
I've seen threads from folks here who have been happy with Bilstein, Rancho, and Fox shocks.