They are very different as you point out. The APCe will probably draw less current but is a bit less efficient at the lower RPM. They are also heavy for use in smaller planes. Do you have a watt meter so you can measure the current?
BTW - I don't use either the APCe or SF type propellers on motors of that size however.
I am really fond of the GWS "HD" (also called Direct Drive) type props for those power levels. They are very efficient!
They make a 9x5 and 9x7.5 that might work well for you. The best thing is I get them from here:
for cheap and cheap fast shipping.
This is the page for the HD series: