Been using the latest PSReadline but CompletionPredictor is awesome and exactly what I've been looking for.

One other PowerShell protip

Ctrl+Space is also another great shortcut for completing commands, it lets you see what type a parameter is expecting etc.

    $ Get-ChildItem -<ctrl+space>
    Path                 Depth                File                 ErrorAction    
    <snip>
    [string[]] Path