I'm a huge fan of the Costco bags. I have the old model Kirkland bag, and it is by far the best bag I've ever used or seen. It has tons of well placed pockets, is of great build quality, and has excellent, hardy zippers. It reminds me a lot of a TUMI bag. In fact, I thought it was made by TUMI because it has almost identical styling. I don't use it for work because I have doubts about it fitting into a CRJ overhead bin. It's my vacation bag.
That said, I was at Costco last week and saw plenty of the new ones there. Don't they still have a lifetime guarantee like everything else at Costco?
Anyhow, if it does turn out that the new one is too long to fit longways into an overhead, consider finding a barely used previous model on ebay. It really is a great bag for the money.