Lots of good advice in this thread. There can be additional considerations, though. In Texas if you qualify with a revolver you can't carry a semi-auto, but qualify with a semi-auto and you can carry either. When I got my first CHL I didn't own anything but revolvers and borrowed a Glock from the instructor to qualify so I didn't have a limitation on my CHL. Before I had to qualify again I picked up an S&W 908 (value version of a 3913). Qualified and put it back in the safe. But somewhere along the line I took the 908 to the range and I gradually got hooked. It kind of opened up a whole 'nother world of weapons.

I still have my revolvers, but sometimes a pistol just fills the bill. Now my rotation is a CS9, 908 or 6906 with a J frame as backup as required.

If one is comfortable with revolvers, there's no need to change. Learning new things is always good, though.