I don't notice any difference. I'm not sure if it's because I am not sensitive enough to notice, or something went wrong with the upgrade for me, or perhaps it is the way I wear the device. Or who knows. The "look at the dot" thing got a lot more annoying though.
Well, the thing is you actually get used to the distortion anyway, but it is very much better now, except some at the very edges. I did an A/B on some star fields, and CA over much of the fov is also improved, but still quite a lot at the edges. I think better than the G2 for CA, but difficult to compare. You have to enable the new distortion profile in VB of course, but I think you did that.
I believe there's also a new option to have it remember your eye tracking setting, so you don't have to press a button to calibrate all the time.