Michael Liczbanski , Nov 16, 2009; 12:13 a.m.
Soft, unless you anticipate checking it in or otherwise need a hard case (for instance to sit or stand on it.) You'll never squeeze as much stuff into a carry-on size hard shell wheeled case as in a wheeled soft case. Check the ThinkTank line of rolling cases. Also, 22" is too much for international travel on non-US carriers, which is important only if you plan on going abroad.