Quick switch between Apps
Using Command + Number key you can easily switch to an app without tapping a bunch of keys.
Convenient Window Switcher
You can also easily switch between windows of the selected application.
Just highlight the app and press E or W (Command-E or Command-W)
When using Command-Tab Plus, by default it displays only the icons of the apps running on the current display or space. Thus, it isolates the apps in one space and the apps in other spaces. Of course, you can disable this function in the app settings.