I purchased a 22" Victorinox Werks after being assured by the luggage retailer and the wording on the tag that it was "carry-on." On the first trip, the bag had to be checked when it didn't fit in the Size Wise because of the handle and wheels.

After raising a stink, we agreed that I would get the 20" bag at cost.

To give you some data to help your decision making process, here's what's happened since:

I've used the large bag for at least 50 flights, and have only been told it had to be checked one more time. It does fit lengthwise in the OH, usually wheels out. It seems like every few months, we hear stories about how DL is clamping down on baggage size, but it always seems to fizzle.

The 20" bag is enough space for a three day trip, including a huge bag of cords, a projector and a second pair of shoes. My jacket is worn on flight, but the suitcase usually includes two pairs or pants, four pressed shirts and the usual socks/underwear. If I didn't have the projector, this would be enough space for a week long trip.

If it were me investing in an expensive bag, I'd go with something that is certainly compliant, rather than something that isn't, but you will probably be okay either way.

On the brand, I've had Tumi, Boyt and now Victorinox. I'd recommend any of the three brands. The Tumi and Boyt bags lasted for four-five years of heavy use, and the Victorinox still looks new after a year-plus. The Victorinox seems to fit the most of the three brands.