Depends on the GUI tool. Some of them do over-simplify things, for example, by omitting the DAG view. This is misleading because it tries to make the source history appear linear when it isn't. GitHub for Windows and Visual Studio's source history both make this mistake, for instance.
Have you tried SourceTree? That's the one I tend to recommend these days. Alternatively, if you're prepared to splash out a bit, SmartGit is worth considering too.