I have several Ace M4 SOCOM stocks in both long and short. They all now sit in the spare parts box.
As others said, heavy and will not take the recoil of anything larger than the 6.8, their words. I had one on my .458 and while they are great at absorbing recoil, especially with the 1" pad, the locking mechanism sheared and collapsed, sticking my beard firmly to the stock with no scissors, knife, or help. The only solution to free myself from the stock, firm up my jaw and pull. Yes, it hurt like a mother******.
That said, if you lock the stock into position it is fantastic on the .458 SOSOM even if it is heavy. Leave it adjustable, especially if you have a beard, you've been warned. I now use Magpul CRTs on all my SOCOMs, .458 and wildcats if I want an adjustable stock, MOE rifle if I want fixed.