I agree totally! Don't get me wrong, my comment was referring to the 8 speed gearbox by mercedes
I myself want to lower my 5th gear, although I must say the gearing is pretty good in mine. 2nd gear gets me to 70, and 3rd gear takes me anywhere from 0 to 90mph... so acelleration is not really an issue for me, but 5th gear at 60mph sits me nicely at 2700RPM... which isn't too bad for cruising in a 1.8 petrol.
I've been wanting to put in the diesel gearbox, or maybe even just give mine the diesel 5th gear (both the same box just different ratios), as it's 14% lower.
I believe these days all cars should have low RPM in 5th gear, using only the other gears for acceleration and 5th as a cruising gear. Or, like the Honda Civic diesel that had a 6th gear for cruising at something rediculous like 1500RPM.