Add my voice to the chorus for PNT. Bought my first one in 1993. Had it back to the company a couple of years ago for replacement of the bottom pan (careless operation over airport curbs), main zipper replacement, replacement of numerous zipper pulls, the business card holder on the back, internal cinch straps, and the back pocket zipper. All were caused solely by aggressive use. Total cost for repairs and shipping - $35. Every item except the bottom pan was replaced under warranty. Total time from when I sent it to STL until I got it back - eight days.
I bought one of the international bags (27") from the MSP Stop Over Store while the old one was being repaired for long trips and for the wife to use when we travel together.
Suggestions:
Buy the metal frame square top bag. This is the sturdiest one - the classic. I used to stand on it to put the engine plugs in the Dash-8 at night (being vertically challenged). Nearly everyone I know who bought the carbonate frame version has not been happy with it. There have been several failures and it torques under the strain of a flight bag and computer bag.
The new stainless steel handle appears very solid.
The new inset main zipper should make for much less exposure to damage versus the old version.
Unless you carry a ton of stuff on overnights or are away from home for more than five days, get the regular (23") size. The bigger one get you into trouble when jump seating due to its size. I rarely have difficulty getting enough stuff in the 23" bag including running shoes and work out clothes.
If you have access to the Stop Over Stores in MSP or DTW, buy it there (or mail order it to save the tax). If you need warranty work done on the bag they will give you a loaner bag while yours is being fixed.
I decided a long time ago that I wanted a bag to keep, instead of buying disposable ones every eighteen months or so.