chattahippie is correct
There are some things that can be done much faster with Axe, but Grammer can have a major size advantage over Axe or assembly programs (and even BASIC-- sometimes). Another nice thing is that Grammer programs can be run from Archive (if the Grammer App is installed).
If you check out the Partex 2 example out, that is an example of a program that would probably be a bit large in Axe, but about the same speed
Still, Axe has its advantages
As a progress note, I have added the Asm( command, so now Assembly programs can be run from Grammer programs! I am still working on some family health issues though, so I haven't done much and I haven't been on much