Been working for 3 years and have probably had 4 costco bags. Never questioned me once about the return. Every time I take it back, they give me a cash card to get another. Works great for taxes. A new reciept every time I get a bag.
They are made very well. My biggest problem on 2 of them has been the wheels, and the 3rd was the handle. If I didn't have to drag my 1,000 lb flight bag around all over the country, it would probably last forever.
Never have problems with overheads in the CRJ unless the expansion part is filled.
SL
Just returned my bag to Costco for replacement. No questions asked, in and out.
Got home with my new bag and hooked up the tote strap to my brain bag and the clip immediatley gave way.

I took it back the next day and cashed out a full return.
The bag is good, but the plastic clip for the tote strap is junk.
Good luck.