keep in mind First Lite Canada site doesn't include duty costs until checkout and I always get a 15% off code for Kuiu 1 item easy from them, Axis shipped here is cheaper.
I own the Axis, they're definitely a warm wear pant and I don't like wearing them until a few degrees below celcius. Great pant used them this fall down to -20C a couple days, vents did their job but like you said a longer vent would help them.
Be interesting to see how these First Lite pants fits, that's my only knock against the Axis is I find they're a bit baggy so will see how the reviews turn out first.