I was going through some tutorials on TortoiseHg. Despite having a rich GUI, the first examples are given using command line options. Does the ideal usage involve command line or it was started that way so one has idea of what is happening under the hood and GUI internally uses this command anyway.
Should Version Control Softwares be used from Command Line or GUI
version control;command line
Use what you want.  Use what makes sense for what you are doing now.While I'm mostly a command line guy (I use the GUI only to get a graphical representation of revision graph), I've trouble to understand why you think using the command line gives you a better understanding of what happens behind the hood (well excepted for GIT :)), usually there is a clear mapping between the two even if CL may give you access to some little used features.Now in my opinion, automating what can be automated in the process is part of the job and for that, CL is mandatory.