That might be true to you but it really depends on what you use the car for. With a slow spooling big turbo you don't have to fall out of the boost as much in a drag race on the 5 speed.

The 6-speed will keep you in the torque curve easier in turns.

If the 5 holds more power then it will be used for the drag cars or high HP track cars. If not it will most likely be used for drag mainly

Ben

 

getrag makes the evo transmission-6spd anyway...not sure about the 5spd

 

You are righ, the case is bigger. Still, I've heard and read that the space needed was still very scarce.... I don't think the MR 6 speed tranny is weak. Personally, I was extremely impressed with the 6 speed tranny and although the gear ratios are not so different from the 5 speed, they definitely feel better (more adequate for each speed) and there is also a noticeable difference in 6th gear cruising... It feels a lot higher that the 5th gear in the 5 speed... I know it's not so much higher numerically, but it feels tremedously different.
The biggest problem I had with the 5 speed is that I always thought it needed another gear to cruise. It always felt it was over-revving while cruising at highway speeds (specially around (70-85mph). It feels much better now anf the gas mileage is improved slightly as well.
Overall, I give the 6 speed the edge in overall driving improvement. Maybe for drag racing the 5 speed is better, but really I don't drag race a lot. Most of my driving requires the use of more intermediate ratios rather than less.