I have never carried a model 19 but off the top, you are going to notice the difference in weight, and it will probably feel heavy until you get used to it, and it will probably be marginally thicker so you will need to let your belt out a notch, and I would suggest carring IWB @4:00-4:30 at a 15 deg cant, it should conceal pretty good there and not be too bad to sit down with