Do a google search on sig customer service and you'll see a bunch of responses, many negative.
I personally have never dealt with them so I don't know how they are.
Depending on where you live $850 for a SIG P229 is almost the same price as a new one...though I think the Equinox may be fancier than just a stock, plain jane P229?
If you get a chance to see it, check the frame rails very carefully for any gouging in the metal.
Turn the gun upside down and look at the frame rails from all angles, with the slide on and with it off.
My P229 (9mm) has gouges on both sides....some say it's from the finishing process, that there is some burr in the metal or something like that that digs gouges into the frame railes as the gun is fired.
Also, if you do get the gun ask how many mags come with it.
They used to come with (2) I heard...but now only come with (1).