I don't know if it makes much difference on the service model. I've got stock sights on my 4", it's my carry pistol. I've got factory installed Trigicons on my tactical competition model. It's also my bedside security.I still have the factory white dot sights and wanted to opinions on upgrading sights. I have never shot Heine Sights before or night sights. Opinions from this knowledgeable group would be appreciated.