I'm finding a flat bar with the ergon gp3 provides me with 2 distinct positions, standard flat bar, and the ends. I had to trim about 25mm from each end of the flatbar to make the 'ends' position comfortable. I have large hands and almost wish I got the bigger GP4 grips.
I'll note that I tried aftermarket bolt-on end bars on a mountain bike and hated them, but it was because they were too wide. OTOH, I wouldn't want to narrow the bar on a mtn bike as you want that wide grip for control and leverage on the rough stuff, but its fine on a mostly-street hybrid.