I swapped from an XTC to the Raven Adventure Tour. This was not because of any dissatisfaction with the XTC, which I loved, but I am planning an End-to-End ride in April/May and decided that I would feel happier carrying my camping gear, etc., on a sturdier bike, especially as I'm hoping to take in some fairly rugged parts of NW Scotland - Inverpolly, Cape Wrath, etc.
The flat bars were one of the big questions in my mind too, but having made the change I am entirely happy. I went for the Thorn Comfort bars with Thorn carbon bar ends and have had no regrets. They are really comfortable, even after 40 miles or more. Another bonus is the fact that I feel more in control, especially off-road on rough tracks, than I ever did with drops. The brakes are right there at your fingertips, the gears are (snick,snick,) almost a subconscious action. As for climbing, it's no harder than with drops. After all, mountain bikes have used flat bars all along, haven't they?
I'm trying not to sound too brainwashed (sad!) as no-one persuaded me to buy this bike. I guess the Raven just suits my kind of cycling.