In reply to buffalo606:
I've tried both those jackets on, but not used them. I have used Rab Neoshell pants (the original version, few years old).
The DWR on the pants did not last long, IMO, so I'm wary of that for a Rab Neoshell jacket.
Rab and Patagonia fit differently. I like the Myriad, it fit me fairly well, you notice the stretch, it's not as billowy around the waist as some other Rab jackets, and it has the long arms and generally slim fit of a Rab. The M10 is a trimmer fit than some Patagonia jackets, but generally they have shorter arms than a Rab and wider fit. Regardless of the brand or fabric, if a jacket doesn't fit *you* well then it won't be any good to climb in. I'm 6'7" tall, 97kg, 34" waist, 46" chest. Tried on XL in both jackets.
Personally I would not want to be grinding up against rock in either of these jackets, I would not expect them to last long. The M10 feels thinner, and has a shinier, slicker outer face fabric than the Myriad.