I have to say that I am a multitool guy over a knife guy. I have LOTS and LOTS of knives. Folders, bowies, khukuris, belt knives, combat knives, hunting knives, even more than a few swords. However, if I could carry only ONE bladed object with me for an extended period of time I would carry some sort of multi or SAK.
Most days I will pack a folder with me like a Spyderco or a Kershaw. They are handy at times depending on the model and other attributes. However, I don't even think of leaving the house without a tool of some sort. It might even just be my Utilikey, but more often than not it is the ByrdRench, Surge, Fuse, or Powerlock. I generally need the screwdrivers, bottle openers, or pliers before I need a blade. The blade comes in handy regularly, so having a folder at the ready is nice for a quick cut. The Rench, Surge, and maybe Skeletool with their one hand opening blade have regulated the folder to a back-up. Generally, I only carry a folder if i can't carry a tool on my hip or want to leave a small print in social settings. YMMV