Graphite: stiff vs. regular

I'm playing regular graphite shafts in my AP1s. Will stiff graphite in the same club reduce twisting, give me less dispersion and make my shots more accurate? I know I might lose some distance, but will I lose the height, too? Would a regular steel shaft be better for me? I've been told I have a smooth swing.

Assuming your swing is consistent, then your speed could cause those effects.  A good Titleist fitter can check your swing and try a couple of options.  The stiff version if it is the correct one for your speed won't decrease distance or loft - ast least not to the point of lower than optimal.

Even for average/lower swing speeds, there are lightweight metal shafts.  The choice would be mostly personal.  I liked a metal shaft better but I told the fitter I wanted them to last 6 years..  I was 61 at the time.  He asked me the odds of increasing my swing speed as I got older.  ,,,I went ahead with graphite (AD55?).  Still love the stock metal shafts in my wedges.