The SLOMO plugin is based on the original loadmodule content plugin, however, it has been improved and new features have been added.
Since SLOMO is a system plugin, it is no longer limited to replacing its tag in the content, instead, you can put the tag anywhere, even directly in your template.
Additionally, it's now possible to display a module by its ID. This is especially useful if you change your modules' names, so you don't have to change the tag since the ID is always unique.
SLOMO is a complete replacement for the original loadmodule plugin, you can safely disable it and use SLOMO instead.