Trying to call MSDeploy from PowerShell but it keeps quoting my source/dest parameters. https://connect.microsoft.com/PowerShell/feedback/details/792571/native-application-command-line-parameters-parsing

Set-WebSiteOffline.ps1

function Set-WebSiteOffline {
param(
    [Parameter(Mandatory=$true)][string]$ServerName,
    [Parameter(Mandatory=$true)][string]$SiteName,
    [string]$UserName,
    [string]$Password
    )
 
    $EncodedSiteName = [System.Web.HttpUtility]::UrlEncode($SiteName);
    $SiteManagementEndpoint = "https://$ServerName.contoso.com:8172/MSDeploy.axd?Site=$EncodedSiteName";
    $Verb = "-verb:sync";
    $Source = "-source:contentPath='`"$SiteName/App_Offline.htm.deploy`"',computername='$SiteManagementEndPoint'"
    $Destination = "-dest:contentPath='`"$SiteName/App_Offline.htm`"',computername='$SiteManagementEndPoint'"
    $Verbose = "-verbose";
    $DoNotDeleteRule = "-enableRule:DoNotDeleteRule";
    if($UserName -ne "")
    {
        $Source = $Source + ",username='$ENV:UserDomain\$UserName',password='$Password'";
      $Destination = $Destination + ",username='$ENV:UserDomain\$UserName',password='$Password'";
    }
    $MSDeployArguments =  $Verb, $Source, $Destination, $Verbose, $DoNotDeleteRule;
    & $MSDeploy $MSDeployArguments
}