Stephanie, by the time you've been through a box of .EDU Ultra 100 or .EDU (aka Classic) 400, you may not want to bother with the Efke. I sometimes find myself (with 4x5) having to think why I'd want ISO 100. Then I remember -- sometimes I *want* a longer exposure (for water, for instance), and the slower film gets me two stops.
Soon, soon, I'll find out how well Type 55 negatives look when processed in Parodinal (the film was free, but it expired in 1987)...