I cannot compare to others' usage, or to Lululemon or Zella, but add another Athleta fan. There are stores here as well. I was very impressed by the fit of both the tops and single pair of leggings I got. I also have quite a few sweater dresses (bought secondhand) that are favorites. They are quality, and although not designed for pear shapes (nothing is), the construction and materials are good enough that they adapt very well.

I think I read most of the responses. I am a long time Athleta fan and have worn their travel, workout/gear, dresses, etc exclusively for decades. I totally agree with all the positive comments others have already made. However, I don't believe anyone mentioned their items GO ON SALE at a much greater discount and frequency than Lululemon. You have to be fast/quick to grab the sale items because sizes run out quickly. I have duplicated many of my favorite items. I don't care for Lululemon for a number of reasons (don't like their fabrics, sizing and lack of sale items and pricing is higher than Athleta for same quality - in US) but I acknowledge they have quality items. You can look at my Wardrobe or collections to see the assortment of items I have if you wish.

I think Athleta quality is very good . I don't have loads of pieces but what I do have wash and wear very well. I have 2 pairs of the Headlands Cargo Tights, they are very comfortable and can be dressed up or down. I have 2 of the Pranayama Wrap Cardigans they wear like iron one of mine has been really abused and still looks ok. I have a couple of pairs of the salutation leggings - I don't reach for those much , I think because the ones I have don't have pockets.
Only downside for me is a lot of their colors don't look great with my coloring !

Zelle - fabrics and seams are just a wee bit unrefined compared to Lulu.

Lulu - great fabric and feel, very limited offerings but extremely consistent

Athleta - more variety but you have to try them on because things keep changing, cuts, materials etc.

Sweaty Betty - love their leggings, they do the best prints.

If price was equivalent, I’s say Lulu and Sweaty Betty are at the top of the heap for me.

I’m a longtime Athleta fan. Their cuts tend to work better for me than lululemon, which is sometimes too narrow in shoulders/hips and often too tight in the legs/sleeves. Athleta’s fabrics are better quality than Zella IMHO — softer, more flexible, launder well. As others have noted, durability and longevity are generally excellent. I like the dark/muted core colour palette, and think they do a pretty good job with their limited seasonal colours too.