Food for though indeed on your observation on weight. On my way back from San Jose my 22-in was loaded up so full that I couldn't lift it. Before I purchased my cases I knew that there would be a slight weight difference between the all wheel and the trolley but that did not come into true realization until I actually had to hoist it into the overhead.
That couple of lbs really make a difference! Maybe I'll go up to a 29in instead.