I'm so happy you started this discussion!
I have purchased
Coach, Juicy Couture, Tory Burch, Ferragamo, Rebecca Minkoff,
Gucci, Marc Jacobs and most recently, Chanel.
I worked at Coach in 2002-2005. The quality was amazing. I probably have owned 30 bags and a ton of SLGs and never had an issue with any of them.
I purchased a Gucci bag in Italy in 2006. The glue came off within two weeks of light use. The US store refused to fix it without charging me about 50% off the price of the bag because I didn't have the receipt. I told myself I would never buy Gucci again.
My Ferragamo patent leather bag was used everyday for two years. It's still in excellent condition.
Tory Burch had the same glue issue as my Gucci. This bag was $600.
Never had any issues with my leather Juicy bags. I have four Minkoffs and there is only one loose stitch that I believe I must have snagged.
I do not have any issue with my Chanel bags or wallet. But I'm scared that my wallet will have the peeling leather. I only use my bags on the weekends, so they are not getting the usual treatment as my other bags.
As someone who typically spends $200-600 on a bag, the Chanel prices are very steep. I agree that a lot of TPFers will show photos of their purchases and think that something is wrong. Usually I can't see it or I just don't expect every bag that comes out of the Chanel factory to be perfect. The frayed leather on some of the rose gold minis is a huge disappointment. My mini does not have the issue, but it still scares me. I don't even know if my bag has the twisted chain issue, as I can wear it fine so I guess I don't have a problem?
So my short answer is this; the bag should be durable with no glue peeling, leather peeling, or hardware that falls off. But loose threads, pockets not aligned, some quilts being puffier than others, or small scratches are OK in my book. I don't expect perfection, but I expect to be able to use the bag for years and years without an issue in the quality. I understand when I buy Chanel that I am paying for the name and to fund all the celebrities in the Chanel magazine, and quality falls lower on the list. I just hope the quality is as good or better than my Coach, Juicy, and Marc Jacobs bags.
And on another note, I know that no one wears Juicy anymore, but I have some beautiful leather Juicy bags in metallic colors that might come out of hiding after this!