I don't have the Spartan, but since nobody has responded yet, here's some related experience. I have a pair of STI Ranger IIs, one in .45 and one in 9mm. The accuracy is close enough on mine that I can't tell the difference. I have 3 STIs and will likely have a fourth in the next year or so. The third one is the Shadow.
I believe the Spartan is the only 1911 model STI doesn't make entirely in house. They have a 3rd party make the major components and then final assembly, fitting, added STI parts, etc. are done at STI. All the reviews I've seen for he Spartan have been good, but I haven't seen any for the 9mm yet.