The gun will have been inspected by a factory smith and broken/excessively worn parts replaced. Sometimes it will be refinished, but lately the refinish jobs have been a bit soft shall we say. If you are wanting a very serviceable weapon jump on it. If you are wanting a show peace be forewarned. The al. frame is anodized and that can't be redone for all intents and purposes. The slide and all other surfaces however can be refinished within a reasonable cost. The main advantage over buying used is the inspection as well as a one year factory warranty.
Everything I've read says they are great guns and offer a great value. Do yourself a favor and google TOP GUN SUPPLY, they are Sig savy and go over the top with customer service. If they don't have something in stock they will not allow you to order it, so no back order shenanigans, and shipping is by Star Trek transporter. Call and talk to them in person for pricing and and ffl lists etc. I'm not a cheerleader by nature but do support those who have done right by me.