The pro comp 6" is not that much bigger than a leveling kit on a 4x4. The newer 4x4s come pretty tall to start with.
I gained 3" when I went from a 2" spacer to a 6" Pro Comp. Its just a matter of opinion whether you think 3" is "huge" or not. My wife is not that impressed by 3" anymore.not true, ive had my truck stock, level,mini lift and now the PC 6" and its way bigger. there is a huge difference once you ad 35's or bigger tires and rims. from a stock or leveled titan to a 6'lift its a huge difference. i have a 4x4 as well