How much was saved by doing this if you don't mind me asking? The times I have looked it has saved $200-$250 which wasn't worth the loss in MQMs and upgrade ability on the domestic segments.
+1... all depends on your routing and the fares available. This doesn't always save as much $$$ as you'd think, and in some cases it can be more expensive. When you ask them to break the fare like this, it means you're essentially buying two tickets: XXX-BOS-XXX and BOS-LHR-BOS. The only way you come out ahead is if the XXX-LHR-XXX ticket in business is more expensive than the BOS-LHR-BOS ticket by at least the amount the XXX-BOS-XXX ticket costs.