I don't know your site picture, so this may be of no use to you. SIG uses a "combat" type sight, that is, you cover the target with the white dot instead of floating the target on top of the sight. Depending on what you are used to doing this can be changed by using a shorter front post, or changing your style.
I ended up changing my style as for the most part I use scopes now. It takes an effort to use irons now that I have adapted to the gun, as most guns are a target type hold.
I would agree on the trigger hook too, they have a really long soft pull, and that may be affecting you.