I recently did a model promotion and downloaded the comparison report. The comparison report ended up being over 1GB in size - prior to this, the largest I've seen is 748KB (we save all our comparison reports for audit purposes).
We did not have an exceptionally large number of changes go in this time (there were 1079 changes but we've had that many before).
Any ideas on why the comparison report file would be so large? I was able to open it in Excel (it was too large to open in notepad) and it was only a couple thousand rows.