This PerfectXL feature allows you to compare one spreadsheet from your portfolio to another on a couple of key aspects. For instance, you can compare an old version to a new version of the same spreadsheet to see its progress.
Spreadsheet Risks & Complexity Comparison
The spreadsheet comparison feature allows you to compare two spreadsheets from your portfolio on general characteristics, risk indicators and complexity indicators. You can compare, for example the average number of non-empty cells per worksheet. Or the number of external references in your workbook. Or the key risk indicators, such as risk dispersion (how many risks per worksheet?) and severity (e.g. how many risks are considered high risks?)