A matter of preference. Personally, I don't get the love for drop bars, I hate drop bars for long rides, they make my arms, wrists and even shoulders hurt. I don't find any position on drop bars to be "natural" and I much prefer flat bars with slight sweep, that is more natural. I never use drops so that's not an issue. So a butterfly bar is the best of both: multiple hand positions and they feel more natural, like flat bars. I have Modolo Yuma which is the real deal, made in Italy for European market and has the best shape IMHO and it is light. The main disadvantages I see is that it may be hard to install some handlebar bags and some gadgets and the main hand position feels a bit narrow, close to the stem, compared to normal bars. But they're very comfortable. I have mine wrapped with two layers of gel cork tape.