You CAN'T power brake with a power bar in the left hand. All you can do is lock up the back and pray.
At first I wanted to switch the brake cables to front brake on the right because its what I'm used to from motorcycles. Then as I got used to the bike, I got over it.
But the longer I ride, the more I realize that I do administrative stuff like eat and drink with the left hand, which means that I give up 80% of my braking power.
So now I'm back to thinking about switching them.