I think everyone hated that SIG gray so much they stopped making it. I got a nice deal on it as they were closing them out (wrong reticle, confused in ordering over the phone, but wanted to shoot it more than change it...and
@BigJimFish says Christmas trees are for suckers anyway
). I subsequently got a Tango4 for a less ambitious project the same way.
I like the gray, personally. I think black is a shit color for guns, generally, and its continued popularity is due more to intellectual laziness and lack of imagination than any other factor or combination of factors.
On topic, the SIG is nice enough...eyebox is tough to get into without a perfectly dialed in stock, but I haven't used it hard enough to generate any other complaints as yet. Both the SIG and the Vortex are heavy enough to make a handy bludgeon...on balance, with a similar price point...well...
I was having his whole debate a year ago....was waiting on the XTR III then...I think we're still waiting on the illuminated models, no? That was influenced by watching a certain forumite punk folks with the XTR II, so maybe worth considering?
I also looked at the aforementioned Trijicon...but, it seems an unknown quantity still. They have been a great company to do business with in the past. My Dad sent in an ACOG for refurb - used to be mine, did some time overseas, got blown up, was missing chunks from the fiber, yadda yadda. Never lost zero, fogged, etc. Trijicon refilled the tritium, refurbished and refinished the optic, and upgraded my 3rd party mount to a BoBro QD free of charge...all of it. I've been looking for an opportunity to kick them some more business since...I just don't buy optics all that often.