Having been through two Perforce -> git transitions of medium sized repos with a few dozen people contributing and being the person with the most git knowledge in the group to be called in when people new to git mess things up: these GUI git clients are ok if you know what you are doing and what the consequences of checking various checkboxes are. They are not conducive to people learning how the tool git works and how to use it to solve real world problems. The command line is a great way to learn git and then fundamental understanding can be used to reverse engineer what GUIs do under the hood.