I knew if I didn't include a section on speed, someone would surely send in a note to MailBITS telling me that I forgot something (not that it will stop you - thanks for keeping me honest), so here it is. I tested both programs on my SE/30 running under System 7. Although 30 minutes may seem like a long time for a Mac to spend on any one task, converting fonts is a lot of computational work, and neither program seemed particularly slow.
FontMonger 1.0.3, 16 typefaces, 29:47
Metamorphosis Pro 2.0, 16 typefaces, 31:35