Collada/DAE Question

I noticed that I can drag a DAE into my assets and Unity seems to treat it just like any other asset. But I also noticed that the file is not converted from DAE to FBX and I'm wondering what impact that has on performance.

I'm not an artist or modeler and I'm most comfortable with Sketchup (Free). I understand the optimization that could be gained with Maya/Max/Blender, but I don't have a whole lot of time to learn those. Should I still convert my DAE to FBX externally first? Or is that not really an issue?

Thanks, Lee