vk55 is basically a cheapened version of vk60. vk60 = vk75 for all intents and purposes. vk75SE is a different animal, and if considering a 75, the se is really the only one to bother with. vk60 is easily the best value of the line, no doubt. vk55 = answer to question no one was asking... aka how to get the vk60 made cheaper and in a smaller box.
-Ed
-Ed