I am in the husky crowd so no help on sizing. i will say, I think kuiu is cut more slim. My last pair were almost skinny jeans fit.
I prefer the attack over the mountain paint for fit and feel. More stretch and comparable wind and water resistance (Don’t expect either to be waterproof). The hip zips are exceptional when it comes to dumping heat. Probably my favorite feature. If I had a knock on the attacks it would be that the fabric picks and pulls. Mine are holding up well but my oldest pair has enough snags that it looks a little shabby. I have also noticed abrasion on the fabric on the hips where my knife sheath and water bottle have rubbed while walking. Knee pads in the mountains are good. Look to the pro pants if you want/need knee pads.
the tiburons and ascents are roughly the same IMO. Both breath well but kuiu gets my nod due to those hip vents. The ascents are more slim cut as I recall. I actually wear the tiburons quite a bit as summer hiking pants and even around town but in fairness, they are solid colored and my ascents are subalpine so are hunting only for me.
if I were updating my pants stable, I would tilt toward kuiu Based on a slightly better fit and feel and those hip vents.
last point, the Sitka offerings are $50 more than the kuiu. on top of preference, I think the kuiu are a better value, although you can close that gap if you find the right sale on Sitka.
