basicly, the lite version comes without double AR and comes with a PVD bezel instead of ceramic. BUT you can add on a ceramic bezel and AR coating to the watch and then its the same as the expensive one.... yet cheaper...
There are one or two very minor visual differences between the two watches other than whats listed above but its not worth the hundreds of $ extra.
if you use the search feature, there is a great review here explaining the differences between the two models.