Definitely size up, the difference is subtle but there, probably works best when you're on hrt and your fat is in the process of redistributing
I bought a small in black. I measured myself and that was the right size according to the chart, but I probably should've gone with a medium. I'm losing weight rn anyway, so hopefully it will work better as the weight comes off.
The shorts only go down about 2/3 of my thigh rn. They are very tight and you have to wiggle around a bit to get them on.
There is some reduction in my butt and they definitely make my lower body straighter. They also have a little string mechanism to tighten or lose the waist which is nice.
The space for the packer is also really nice. If you have an actual penis though the crotch might be a bit tight.