batsbrew
it only makes sense to learn the shortcuts that a software designer has decided on,
usually there's a good reason they are they way they are.
I'm the one who did the mappings, and I agree 100%. There are many functions that have no direct equivalents. Also, to map a SONAR shortcut often means overwriting an S1 shortcut that does something else. Furthermore, there are functions in both programs that have no direct equivalents, but they also don't have default shortcuts so if you have custom SONAR shortcuts, you may be able to use the same shortcuts in S1.
The mapping is best for those who want to try out a demo version as easily as possible. If you end up deciding you like S1, then it's indeed worth learning the shortcuts the designers created.