I ordered an XCR-M from my local retailer and it actually came in from Wolverine with the new stock already on it (also the new muzzle brake). Anyone have any questions?
This new stock is definitely sturdier and less wobbly than the older FAST stock. I personally find the flat-top cheek riser to be more comfortable as well, and have no issues getting good optic/scope alignment adjustments with it. When it comes to vertical adjustments for the cheek riser, the stock functions just like the older model. The top plastic piece can be slid backwards and then slots forward into one of the three available slots. The previous stock only had two options here for height. You can get more vertical adjustment by undoing the two screws after folding the stock, then lifting the whole stock assembly up and screwing it in place in the higher position.
Length of pull is now adjusted with two push-buttons on either side of the stock. Both buttons must be pressed inwards towards each other. You can then adjust the length of pull while holding these buttons inwards. The screw/knob on the very button of the stock is tightened to prevent any wobble in the stock.