I just got my 24/7 C DS. I wanted a firearm I could carry that did not require me to use two hands to cock it if someone was throwing lead my way. My ideal was a decocker with a thumb safety since you can have a DA trigger pull and a manual safety. If you have a decent holster, the trigger is covered to prevent Glockitis (shooting yourself in the leg/nutz). If you are drawing correctly, you won't have your finger on the trigger until it is needed.
I couldn't imagine having to rack the slide in an emergency. The DA feature means that should the safety ever not engage properly, you have the added security of knowing that it takes a complete long pull of the trigger. Of course, these are all issues of personal preference. I like to err on the side of safety when dealing with firearms.