I love it. I have the LA10-DS and I'm a big fan of that version, but the -M is pretty much better in every way. Some quick thoughts:
The -DS version was cut quite short in the back, the M is slightly longer which makes it much easier to wear IMO.
My biggest issue with alpha direct pieces in general is that it's very hard to layer with b/c the fleece has a lot of friction. The LA10 is basically a vest in that the alpha direct lining stops at the shoulder, and because it's cut quite wide, you can layer quite a bit underneath if needed.
The -M variant has the two zippered internal pockets which are great addition. I wish the -DS had them as well, especially when slung, I don't always trust the front pockets w/o a closure
The front pockets are massive and completely hidden. I sort of wish they were also lined in alpha direct as hand-warmers, but it's not a deal breaker for me.
I think I prefer the jacket sling on the -DS to the shirt sling on the -M, but it's very low-profile and easier to layer with so it's growing on me.
It's warm af
Lastly, I picked up the grey color and its fantastic in person – has a bit of an olive tint to it.