A 16-LA will have the loader frame hit the wheels. The 17-LA is for use with Supersteer tractors, as it is several inches longer to allow for the increased front wheel movement. The dealers I've been to price the 16 and 17 the same.
I test drove a Supersteer TC40D yesterday - it's almost scary how far the wheels will move in the direction your turning.
I would have to agree on the super steer! It is amazing!/w3tcompact/icons/smile.gif It makes a class III Boomer handle and maneuver like my class II....simply amazing.
I was told the same thing on the loader. The 17LA is longer so the front tires won't hit the loader. Price is the same.