I always have my sp101, but I call it my bug. I usually carry my XDSC.40 too and call it my primary. I know I sort of have them labeled wrong since the revolver is ALWAYS with me and the XD isn't.....I just like the concealment of the ruger IWB better than the XD. I can't find an IWB holster that I like for the XD or it would become the "always with me" gun and something else (bigger) would take it's place as the "usually with me" gun, maybe the XD.45 or the .44mag revolver.....
short answer, BOTH. Semi automatics are known to jam...revolvers not so much......
always an auto. I like wheel guns for target. For the width of most wheels guns, I could carry a 15-18+1 9mm, so I usually carry full size auto, or smaller capacity pocket pistol.
I carry a wheelgun. I feel they are safer, I always know if there is one in the chamber. I don't have to worry about any FTF, or FTE. I usually carry a S&W 638 or a Charter Arms Bulldog .44 special.
I carry a glock 23 most of the time mainly for the round capacity and also the fact that is has night sights. Occasionally I will carry a j-frame though just for ease of carrying.
I carry a S&W 642 everyday due to concealability, but I've never thought of it as my "primary" weapon. When I'm out on my own accord I carry a G23 on the belt with the revolver as backup.
I agree with some of the others; it's all in what you train for and are confident and comfortable with. I go back and forth. I just make sure to train as much as possible with either or both depending on the combination I'm carrying.
All of my revolvers are DA, and for some reason it just bothers me to carry them. At one point I carried some of my revolvers with the first chamber empty, but over time I ended up carrying my SA more and more until it just became my "always".