After reading all the reviews on this 21" carry on, I made the purchase.  Granted, I've only used the item for a few days, so I won't speak to its long-term durability.  But everything from the outer fabric to the zippers look solid.  The zippers on mine were not "sticky" at all and were very easy to open and close.  Not only is this a solid piece of luggage, but it looks great too.  I have bought most of my luggage at Costco over the last 5 years.  But I'd have to say this is the best-looking and most solid suitcase I own.  And the price was very competitive.  This case fits easily in an American Airlines MD-80, so I assume it will fit in the overhead of most aircraft.  A good purchase and, as usual, good service from Amazon and the seller.