dtc, please do let us know what your face to face comparison comes up with. That's very interesting. IMO, it's stuff like slightly different materials and features like different wheel bearings that make the price difference, but the biggest one will be the warranty.
When you consider different suitcases it is good to consider their weight as one of the most important factors. You are fighting against a 50lb limit. The less the suitcase weighs, the more you can load it to the limit.
Forget about the suiter. While TP does make good ones, it saves a lot of space and weight if you just learn to fold a suit correctly (takes 5 minutes) in the link oshelef kindly provided.
Cheers,
Till