I use drop bars but I'm rarely in the drops (most downhill and some headwind). If I used flat bars, I'd absolutely need bar-ends as I find the "plain" flat bar position unnatural. To illustrate, stand with your arms at your side, then lift your forearms. To grab flat bars, you have to twist your arms (thumbs in, palms down). I feel tension and I'm not even grabbing anything! I don't like the break position on flat bars either. I've been thinking about bullhorns for my next bike. My 2¢.