Größe eines Web berechnen

Hat schon einmal jemand versucht die größe eines Web zu berechnen? Für Sites kann man ja einfach das folgende Statement verwenden:

Get-SPSite | select url, @{label="Size in MB";Expression={$_.usage.storage/1MB}}

Bei Webs scheint das ganze etwas komplizierter.
Ich habe mal das folgende Skript verwendet um eine Näherung zu erreichen - ich hoffe ich habe nichts großes "vergessen":

function Get-SPWebSize {
   <#
      .SYNOPSIS
        Measures the size of an SPWeb - be warned that this is only an estimate, 
        as SharePoint has no OOTB function to measure the size of an web.
   
      .PARAMETER Web
        the web to measure
 
      .PARAMETER HumanReadable
        whether the output should be human-readable (KB, MB, GB, TB)
   
      .EXAMPLE
        Get-SPWeb path/to/web | Get-SPWebSize -HumanReadable GB
   #>
   [CmdletBinding()]
   param (
      [Parameter(Mandatory=$true, ValueFromPipeline=$True, HelpMessage = "the SPWeb to measure")]
      [Microsoft.SharePoint.SPWeb]$Web,
      [Parameter(Mandatory=$false, HelpMessage = "set to a size to measure in (e.g. KB or GB)")]
      [ValidateSet("None", "KB", "MB", "GB", "TB")]
      [string]$HumanReadable = "None",
      [Parameter(Mandatory=$false, HelpMessage = "Suppress the startup-warning")]
      [Switch]$SuppressWarn = $false
 
   )
   if(-not $SuppressWarn) {
      Write-Warning "Be aware, that the calculated size is only an estimate!";
   }
   if((Get-PSSnapin Microsoft.SharePoint.PowerShell -ErrorAction SilentlyContinue) -eq $null) {
      Add-PSSnapin Microsoft.SharePoint.PowerShell
   }
   function Get-FolderSize {
      [CmdletBinding()]
      param (
         [Parameter(Mandatory=$true, ValueFromPipeline=$True)]
         [Microsoft.SharePoint.SPFolder]$Folder
      )
      [long]$size = 0;
      $Folder.Files | %{
         $size += $_.Length;
      }
      $Folder.SubFolders | %{
         $size += $_ | Get-FolderSize
      }
      Write-Verbose "Folder $($Folder.ParentWeb.Url +"/"+ $Folder.Url) has size of $size";
      $size
   }
   function Get-SubWebSize {
      [CmdletBinding()]
      param (
         [Parameter(Mandatory=$true, ValueFromPipeline=$True)]
         [Microsoft.SharePoint.SPWeb]$Web
      )
      [long]$size = 0;
      $Web.Folders | %{
         $size += $_ | Get-FolderSize
      }
      $Web.Webs | %{
         $size += $_ | Get-SubWebSize
      }
      Write-Verbose "Web $($Web.Url) has size of $size";
      $size
   }
    
   $size = $Web | Get-SubWebSize
   if ($HumanReadable -ne "None") {
      $size = Invoke-Expression "$size / 1$HumanReadable";
   } 
   $size
}