Practically speaking, although at first I thought it was a good idea, but now realize this isn't much of an improvement. I tried using auto mode after the change but found it was so irritating that after starting off I immediately pressed the paddle to shift to manual mode anyway.
If you do use the "auto" mode primarily it will at least allow you more control over engine rpms when you need it - but why not just use the manual mode instead? Besides, it was easy enough to just nudge the shift lever sideways to go from auto to manual or vice versa. There is no advantage to keeping it in auto mode. Shifting by using the paddles or even the shift lever is so easy and intuitive that it is irrational to put up with the nonsense of that poorly implemented auto mode. This modification was a partial attempt to mitigate the problem.
As far as quicker shifting is concerned, there is really not much change at all. I did notice that the "creep" is more gradual though. That never bothered me anyway because I always put the transmission in neutral when stopped.
Although the shift mapping in auto is related to fuel mileage and they probably didn't want to change that, it should have also been altered to shift gears at higher rpms.
Get it done by all means, but don't expect miracles. Because of complaints regarding the "auto" shifting, my understanding is that a focus group was used to determine the best compromise to improve matters and they came up with this solution.
As far as I'm concerned, the best solution would be to get rid of the PRND consol, advertise the car as a clutchless manual, install tachometers in every model, and teach those unfamiliar with manual transmissions what to do. It's so easy to shift manually with this transmission that a child could learn and do it proficiently in a matter of minutes. An advertising campaign related to that would do wonders to car sales and eliminate the major complaint of virtually every reviewer of the smart car. It has a wonderful manual shift but a ridiculous auto shift. Change the focus from trying to sell it as an auto transmission and instead market it as a fun and easy to drive manual (which it actually is).