I have not used the holster you listed. I am a lefty too. I do use a Blackhawk serpa for my 5 inch 1911. I use it to compete in IDPA. It works great for me. Not sure if it comes in a 3 1/2 inch. How do you like that Springfield?
Romans 1:16 I am not ashamed of the gospel, because it is the power of God for the salvation of everyone who believes: first for the Jew, then for the Gentile.