Yes, just by clicking on your post, this forum system lists at bottom 4 "similar threads" on comparing extracts and there were a bunch of others. But it's really hard to come up with objective conclusions, partly because it depends what else you mix with it.
It can be quite counterintuitive because if you decide it is too sweet for instance, it may actually benefit from adding less sweetener - there is some particular balance of sharp (almost foul) extract flavors and smothering sweet that totally transform the results. And for instance I found the zaterain almost undrinkable without using expensive agave sweetener.
