A nice thing about Maya pie (marking) menus is that you can go many levels deeper with just a gesture.
Here is what I mean:
Although I use this rarely I thinks it’s an useful functionality.
Also Blender automatically assigns a key for the different buttons in the menu. This is maybe useful sometimes, but causes problems if you set the hotkey for the menu to a key + mouse button.
For example if you set the hotkey for the snap pie menu to “S + Left Mouse” (currently Shift+S) when you try to call it it will immediately choose the menu item containing “s” (Selection to Grid) and it won’t let you use the pie menu.
Maybe I should report this as a bug?