I recently put the hi/low boost back for a longer trip through the snow, thought it would be smarter and it's a 2 sec job anyway. When I arrived at the destination though I immediately changed it back. That was the most boring drive ever. Overtaking in 5th gear etc on the motorway was just horrible. On the other hand it did obviously work when your driving somewhere remote in town, pulling away etc. is easier, but then when you want the power it's not there. Did get great mileage though on that trip with low boost on all the time, but that could just as well have been because of the 'drive-it-like-its-a-prius' driving style in the snow, e.g. braking on the engine, driving around at less then 2000 rpm.