The "wheelies" type suitcase are becoming popular in the US for good reason.  Great for menuvers in tight spaces, airline aisles, or lines.  Now I understand why the Asians have been using the four wheelers for decades.  I selected this particular unit since it has eight wheels.  Moves easily on carpets, balanced when used in the conventional manner, and is well made.  A quick spray of silicon on the zipper allows for smooth operation, with no need for "break in".  As is a carry on, so I'm not concerned about scuff marks or rough handling.