Alternatives to SyncToy

unction rcopy {

  Param (
  [Parameter(Mandatory=$true,  Position=0)] [Int]  $type,
  [Parameter(Mandatory=$true,  Position=1)] [Int]  $rty,
  [Parameter(Mandatory=$true,  Position=2)] [String]  $src,
  [Parameter(Mandatory=$true,  Position=3)] [String]  $dst
  )
 
  $s = '"{0}"' -f $src
  $d = '"{0}"' -f $dst

Write-Host `nSyncing $s to $d

# type 1 is copy 2 MIR
#
$mt = 1  #for /MT:$mt
#
  switch ( $type )
  {
    1 {  $p = Start-Process -Filepath "C:\Windows\system32\robocopy.exe" -ArgumentList   " /s    /MT:$mt /A+:N /B /R:$rty /W:2 /NFL /NDL /NP /NJH  /SJ /XJ $s $d"  -Nonewwindow -Wait -PassThru }
    2 {  $p = Start-Process -Filepath "C:\Windows\system32\robocopy.exe" -ArgumentList   " /MIR  /MT:$mt /A+:n /B /R:$rty /W:2 /NFL /NDL /NP /NJH  /SJ /XJ $s $d" -Nonewwindow -Wait -PassThru }
  }
  $code = $p.ExitCode
  Switch ( $code )
  {
    16    {"Robocopy: Fatal Error"}
    15    {"Robocopy: Successful copies with failures, mismatches and extras"}
    14    {"Robocopy: Failure with mismatches and extras"}
    13    {"Robocopy: Successful copies with failures and mismatches"}   
    12    {"Robocopy: Failue with mismatches"} 
    11    {"Robocopy: Successful copies with failure and extras"}   
    10    {"Robocopy: Failure with extras"} 
     9    {"Robocopy: Successful copies with failures"}   
     8    {"Robocopy: Failure"}
     7    {"Robocopy: Successful copy with mismatches and extras"}
     6    {"Robocopy: Mismatches with extras"} 
     5    {"Robocopy: Successful copy with mismatches"} 
     4    {"Robocopy: Mismatches"} 
     3    {"Robocopy: Successful copy with extras"}   
     2    {"Robocopy: Extras"}   
     1    {"Robocopy: Successful copies"}
     0    {"Robocopy: No changes"}
     }
   }

/J :: copy using unbuffered I/O (recommended for large files).