Cheers Beacon, well put.
If you isolate payment protect loans only. XIRR will show 40-50%... Massively inflating your return if using the method Alistar_Mid is using.
Never said I was clever. However unless you have largely avoided payment protect loans - your XIRR will be overinflated.
The rest of my tool is technicality (although correct). It enables some cross checkign against RAR. Once I've gone through a cycle of loans, I'd be happy with 7%.... Who knows whats to come