Is ABS a good luggage material?

ABS is light, rigid and cheap, and it handles normal travel fine. It is less flexible than polycarbonate or polypropylene, so it is more prone to cracking if a bag is thrown or crushed hard.

Does every piece have a TSA lock?

The set lists a TSA lock as a property, but budget sets often fit it only to the larger checked cases. Check each size before you rely on it for international travel.

Can the cases nest inside each other?

Yes. The five sizes are designed to nest, so the smaller cases store inside the largest. That saves space in a closet but means the full set takes up one large bag's footprint.

Is this set good for checked baggage?

The larger pieces work for checked travel on occasional trips. For frequent flying or heavy handling, a polycarbonate or soft-sided bag with a stronger frame will hold up longer.