Most likely going with Sig for the new rifle.

While the Colt SP901 is pretty temping, so is a gas piston AR 10 made by Sig.

From Sig's Facebook Page

All ready has the ACS stock I want and may be a little lighter than the Colt sans the monolithic upper. How did I miss this at SHOT?

There's also a "Precision Marksman" version with a longer rail and 20" barrel, specs show less than two pounds of difference, 9.3 vs 10.6 lbs. But I'd have to buy the ACS stock anyway and eBay the PRS from the Marksman model. The ACS is less clunky with no funky wheels and stuff, has a cleaner look and a better spot  (a'hem "cheek") weld than most of the other stocks I've felt. I wonder if an extra 4" of barrel and longer rail is worth the weight, it's not like I'm going to he hiking in Afghanistan with the thing and some moderate range coyote hunting may be in my near future.

Guess we'll wait and see how the pricing between the Cotl SP901 versions the Sigs compare.