Call the company and ask them:
The Neat Freaks Closet Solutions, Inc
Toll Free Phone:
800.690.6377

Would like someone to answer who actually has the system. I'm afraid of biased answers from someone who works there.

Hmm, I'd give them a call too. Perhaps someone has used the exact system you're looking at, but anything mounted to the wall will hold a substantial amount of weight for closet-related items. If it's freeform and wouldn't support your suitcases, I'd be terrified of hanging a row of shirts and hangers!

From their site linked below:

How is the closet shelving mounted?

Pine - Our John Louis Home systems are "off the floor" mounting systems. We utilize three universal bracket types that are secured onto the walls. The shelves are then locked into the brackets. Since the shelving covers the majority of the brackets, minimal hardware is in view. Because the closet system is raised, floor space is open and clear of any obstructions.

Hardwood - Our hardwood systems can either be "off the floor" or rest on the floor, depending on your desire or need. There is no metal hardware with these systems. All of the supports are made of Ash Shelving connects directly to other shelving, creating an "all wood" look.

I think the shelf would hold it just fine, ie would not break of buckle. It is the 'proper' installations of the brackets by you or an installer that holds the shelf, that would be of greater concern to me. Properly anchored into studs should surely hold the weight of suitcases and more.

Here is a link that might be useful: Neat Freaks

I agree with contacting the company just in case :)