So my new (last year) bike came with SRAM everything.
Including GX/NX 12 speed.
Now that I've had time to put some k's on the bike I think 12 speed is over-rated. (regardless of brand...)
At first I thought, "...Cool, 12 gears must be better than 11 for my lazy fitness levels....this will be sweet for climbing..."
....but in reality it's a pain.
Because many of the gears are quite close in ratio....I find I am changing gears a lot more often as the trail undulates compared to my old 1x11 bike.
This is most noticeable after a short climb when you want to get back down the cassette and accelerate. With the 12 speed it feels like I have to shift down the cassette eleventy million times to get some real power into the dirt.
Many might disagree, but I think 1x11 is actually the sweet spot for most trails, most riders, most bikes. Plus it's a little lighter (in theory) and a little cheaper.
When my current drive train is toast I reckon I'm gonna replace it with 1x11 Box Components / Microshift / Sunrace / other? / NOT-SRAM / Not Shimano.