Just like rjcorazza, I bought the 4060 because of the engine itself rather than the horsepower difference.
The L3560HSTC-LE and the L3560HSTC use a 3-cylinder engine. L4060 and up use a 4-cylinder engine. And as was said, it is the same engine as the higher models, just without the turbocharger. The 4-cylinder is a little bit smoother.
Also keep in mind the LE (Limited Edition) model you are considering is lacking features found on the regular L3560 and L4060, such as the front work lights, 12V outlet inside, cruise control, outside mirrors, and the right-side door step. For those who say they don't need the right door step because they never get in or out on the right with the loader stick in the way, I've done it on multiple occasions. Where I park the tractor there isn't room for me to exit on the left side. I'm 6'5" 250lbs and I can fairly gracefully enter / exit on the right.
Either way, its a great tractor though.