Here is a neat Powershell script that:
- Finds all Domain Controllers in the Domain (using .NET)
- Creates a contact object in a specified OU (Default is users container for the Domain)
- Gets the start Time
- Loops and Checks each DC for the object.
- Once all DCs have the object it gets End Time
- Outputs the results
Basically you can check how long it takes to replicate to each of your sites. Very Usefull !