Pick a program, stick with it, and ignore the other programs.


Or, draw a line (date) in the sand, and declare iPhoto the program of choice for photos before a certain date, with Aperture the program of choice for photos after that date.


Or, do the above but convert RAW to DNG (if Aperture supports that). Go back through old pictures AS NEEDED and convert to DNG; any folders where you have DNGs are assumed to be in your newer software.