1--The back rise does feel too low.
2--In action, it's actually fine.
Montanan, 5'10", 190#, usually b/w a 12/14 size, curvy hips. Ordered "up" to an XL.
First try on, I was annoyed with the back rise--felt like if I bent over I'd expose my backside. Having read the reviews complaining about this, I had to agree that it seemed like a silly design problem and I intended to return them. But... I got behind and then I needed them for a really cold day of snow activities so I went ahead and wore them. So glad I (accidentally) kept these!!
I never even noticed the back rise issue when I wore them out. The Noras are serious leggings, for when I'm spending extended time outside and really getting in to Winter. (*I also have the Stella leggings, and I wear those for work or less cold activities--they're a perfect blend of merino warmth + stretch and fit of true leggings.) If I was sitting around in the Noras, I can see how the rise might bother me. But when I'm active (skiing, snow shoeing, shoveling the walk), I'm upright and moving and they're completely fine. Admittedly, I've got my base top tucked in to the leggings (then next top layer alternatingly tucked in to my snow pants, and so on) so maybe that's why I never noticed the rise in action (like I did just standing there in my closet). But I've worn these doing a bunch of activities and I Honestly haven't had any issues--no pulling them up, no feeling like they're too low on my butt, nada.
Other quick notes: Length is fine for me (another 1/2" would be a nice bonus but it's not a problem), thickness and weave is spot on, they're as warm as the Patagonia Air Capilenes I've been wearing for the last decade.
Bottom line, the back rise turns out to not be a problem. Length is perfect, thickness and weave is spot on. The Noras are fantasticly warm and these were with the investment.