It looks like the Money performs all math that might have fractions of cents using a RoundingMode. This will cause issues with multiple operations and money loss. If you multiple by a couple of numbers, do some division, add a few things, do some more division, you'll end up losing multiple cents along the way. This happens frequently in financial applications and many others as well.
There needs to be a way to perform multiple calculations on a Money instance without any rounding and then round at the end. The BigMoney doesn't quite provide this. Perhaps a MoneyMath container (or building pattern) of some sort that can provide multiple operations and in the end provide back a Money instance.
I guess I'm not sure exactly what you're looking for. BigMoney simply wraps a BigDecimal, and should expose all the key methods to do what you want. Perhaps there is a method from BDecimal that it should expose but doesn't? Happy to take a look a pull requests if that is easier..
Please see https://github.com/gigs2go/joda-money-calculator for a simple implementation (also includes #4)