The 71 is a bit of a different shape compared to the bigger EVO IQs, concave into v and more rocker - a more direct offspring of the old EVO (70) and ET (70, 74), but in a more modern and compact shape. SO even if you could decide a "winner" among the bigger, more similar ones, I don't think you can as easily compare the 71 with the others. It's more "different".
So the question more becomes what you are after. After riding the 71 (in twin mode) only on slow, mushy cross on, I'd say that it's a super easy and stable platform which sort of feels bigger than the 71 liters. Good drive in the slow waves. It goes vert nicely too, but instead of a nervous, edgy looseness it's has a more forgiving nature to it. I'm guessing it's gonna have a HUGE range, by virtue of being so composed I think it will really work well in powered up conditions too, despite feeling a bit big. The 76 has a more "crisp" feel to it. Faster feeling in marginal conditions but also harder in powered up stuff.
So, what it it that you're after?