I have a 340PD that has been carried daily for 3 years. I use an Uncle Mike's #3 pocket holster.
The gun has no finish wear at all, and looks great. I clean it with Slip2000.
I own a 340PD, and I don't think it is an issue of the shells sticking.
If you use less than 120gr bullets, the recoil could possibly unseat the bullets from the case, and bind the cylinder.
I would take the 340PD...lighter weight for CCW, ammo restrictions not that big a deal, and easy to clean.
I have owned and carried a 340PD for 2 years, and would buy it again without reservation.
I own a 340PD with a Ti cylinder, and it is my daily CCW. I clean it with Slip2000 or EEZOX, and it looks great.
The S&W owner's manual cautions you not to clean the Ti cylinder with harsh abrasives, sandpaper, or scotchbrite pads.
I hope S&W continues to make new models with Ti cylinders.