I don't think you are going to like these numbers if you are wanting to drop SRAM.
The graphic shows the gearing inches for a 27" wheel.
The 28 ring with the 42 cog is the best climber
The 30 ring with the 10 cog is the highest speed.
The Shimano 46t xt cassette is middle ground on both ends (not a huge difference really), BUT it is an absolute boat anchor when compared to the SRAM cassette.
439g Shimano XT 11t-46t cassette
268g for XO1 10t-42t cassette
For reference a RF Cinch DM ring 30t is 54g
There is a 1/3 pound difference (171g) in the cassette weight. Iâd stick with a Sram cassette and pedal a little harder on the climb.

Too Funny Dean, I was looking into just this earlier today……
I checked my gear ratio charts and its shows the Shimano XT 11-46 cassette with a 32 ring to be comparable to the Sram 11-42 with a 28 ring, buy yah LOL , I saw the weight penalty for the XT cassette and I choked. I will be installing my Sram 11-42 cassette and my spare 28 tooth ring asap. That's 1/4 to 1/3 a pound saved right there!
However, once I chew up the 42 tooth I will put a One Up 44 on and jump from 28 ring to a 30 and should still have the same climbing ratio but a little on the top end which can only help