Just real-world indicated figures here. Going down the highway at 70mph (indicated) shows 2500rpm (indicated).
I live in a warm climate. I have not noticed any peculiar notchiness/sloppy/stiff problems with shifting, other than that it has become smoother over time. That's my experience only.
I understand that cables could cause a different feeling than rods. What are you doing though? Drag racing every day?
The gears may have been thinned to accommodate the 6th gear but I have not read of any massive failures.
I've been driving manuals for a long time. It's just fine. I do understand that others could and will have different experiences in more severe climates.