I recently got a tour bike that has drops despite having 26" wheels and I am thinking about swapping to a butterfly/trekking bar. I haven't ridden a drop barred bike for years and just cannot get comfortable on it. The hoods should obviously be the default position but although having the wrists angled so the palms facing is good other aspects of the position are not so good. The angle of the bars means the wrist is angled back ie extended on the thumb side. The bars going down mean that you can't grab the bar properly and I find that all my weight either goes on the webbeing between thumb and fingers or the bar digs into the middle of the palm. Even on relatively short rides, 12-20 miles, I find it very uncomfortable and get numb hands.
I have also noticed that despite people on here and another touring forum I go to seeming to prefer drops most of the blogs I see of people doing long tours they are mostly riding mountain bikes with straight bars and bar ends.
The problem is that swapping to trekking bars will be a big job as it involves changing brakes, f.derailleur and levers. Although swapping to V brakes instead of cantis + drops is a big atrraction. If I could find a suitable mtb frame I may just swap bikes instead of going through the hassle of swapping the bars and bits on the one I have.