Very nice!!
Re longer 5th gear, as a daily driver, thats one thing that I really found annoying in the turbo, 3000+rpm on the highway, a drop to low/mid 2000rpm would have been awesome from a noise POV, would have made it much more relaxing on longer trips. The extra fuel economy would have been a bonus, although it was quite good anyway, low/mid 8litres/100km from memory.
I doubt the performance would decrease significantly, and you can always dop back to 4th if required.
As you have everything accessible, now might be a perfect time to do the mod?
Cheers