profile.ps1

Update-TypeData -TypeName Object -MemberType ScriptMethod -MemberName SizeOf -Value {
  param()
  if($this -is [type]) {
    $SizeOf = [System.Runtime.InteropServices.Marshal].GetMethod('SizeOf',[type[]]@([type]))
  }
  else {
    $SizeOf = [System.Runtime.InteropServices.Marshal].GetMethod('SizeOf',[type[]]@([Object]))
  }

  return $SizeOf.Invoke($null,@($this.psobject.BaseObject))
}