it depends on what you're doing on whether or not the 6 speed is worth it or not in this case. daily driving and dragging it's worthless, just an extra shift. road course and autox it's worth it.
from hanging out on evom my impression is that most people who get the MR buy them and they treat them like these super special things and either hardly drive them or don't drive them hard. lots of them change the wheels too. they get the MR then treat it like a show car, never seeing rain, dirt, anything fun. they got the MR just because it's the best, plain and simple. just an fyi, all of the really fast/shop evos are 5 speeds.
would i rather have a 6 speed? honestly, i could care less. obviously i chose the 5 speed, but i guess if it was the same price, same strength, etc..., i'd go for the 6, but there's enough power that the extra gear isn't going to make much of a difference