Hi Bob,
Yes, we've got 6 pot front brakes on a couple of our Carawagons, and they are very effective.
However, I've still got standard 4 pot front brakes on another (with servo), and I can still lock them up in an emergency stop, as demonstrated on the way back from our last pub meet when a car pulled out from a side street, between parked cars, and "didn't see me"

I left a couple of nice black marks on the road, and a frightened driver who suddenly saw me bearing down on him - I came to a stop just a couple of feet away from his driver's door
He's probably very lucky I've got Michelin Latitude tyres on that one, and not the old Avon Rangemasters I used to have!
Robin.