this is kind of like asking about seats, hard to get an informative answer as it is personal. I have not ridden with these, but do ride and have toured on straight bars, risers actually with a slight rear angle to teh grip area and also using bar ends to give some diff positions. Certainly from my experience, these sort of bars may be nice as you will clearly have diff hand positions that will change the angle of your back and neck, but when I looked at them, I wasn't willing to spend "I cant remember how much in Canadian dollars" to see how they are (I forget the number, but it was probably 150bucks)

re stem, given how far back the area of the bars with the brake and shifters are, compared to a more regular flat or riser bar, you may find you need a longer stem in fact, not shorter.
Also, notice that there is essentially no rise to these bars, so take that into account for bar height in relation to your seat, and therefore playing around with stem angle as well as length may end up having to try diff stems to see what works for you.
I can only say that the increased angle of my risers was a nice change from relatively straight bars, some people like this radically more angled hand position , some don't....which leads back to my opening comment....and are you willing to spend X dollars to try them?

ps, just looked up prices, 125US, so for a Canadian, you're looking at OVER 200 bucks to try out a set of bars...ouch.