Long story short, I am looking for a parawing that can continue the fun when winging is not enjoyable. That's 40+ knots for me as the upwind gets really chore like.
Going upwind is always going to be a chore in anything over 30-35 knots. Doesn't matter if it's a wing or parawing. That's because the projected area of your body + board + mast etc starts to become significant relative to the size of the sail / wing, which is all that's powering you upwind. You know that's the case if you have to walk upwind with your gear.
But if you have a situation where the current is pushing you back upwind it changes the equation completely.
I've had some amazing 30+ knot sessions on my 1.8 brm. The angles aren't as good so the runs are short, but the epicness of the terrain more than makes up for it. But when it starts to get close to the 40 knot zone even on the 1.8 it's a real handful. I suspect the V2 ka'a will handle better, but comfort in sustained 40 kn might be asking a lot.