The EinsteinExact arrangement provides initial data accurate to roundoff, in contrast to the Exact thorn which does not. The initial data from the Exact thorn is also highly sensitive to roundoff level differences.
Hence, tests should be converted to using the EinsteinExact arrangement where possible. In some cases, EinsteinExact will not support the required metrics or parameters. These could either be added to EinsteinExact, or the Exact thorn could continue to be used.