I've carried for over 30 years. During that time I've tried many different spoons. I currently use a Glock model 42 (.380) because it's light and has proven reliable for me. The manufacture will be releasing a single stack 9mm in Feb 2015 and I will most likely switch to that because I like that round. Something to consider when choosing a concealed weapon is how comfortable will you be while carrying it. If it's too heavy or big you may start leaving it at home or in your car. That is what usually happens to me when my choice at the time is something bigger than I can conceal comfortably. JMO.
P.S. If you choose a semi auto please train for failure to fire, failure to feed, failure to extract, double feeds, stove pipes and failure to eject situations. Also learn what a squib load is and how you should handle it. Thankfully they are rare. btw, with a snubby revolver except for a squib load, you really only have to train for a failure to fire and the solution is to pull the trigger again
Stay Safe !