I've never tried the launch mode and doubt I ever will.
I do use "S" mode manual all the time, however, as it's a good way to limit unnecessary gear changes when cruising on rolling roads. For example, if I'm cruising at 60mph on gentling rolling roads in "D" mode the car will tend to downshift when climbing even a slight grade but if I have it in "S" mode manual and put it in 6th (manual) the car will not downshift unless the speed drops too much. I'll leave it in 6th unless it drops a few mph then thumb-shift down as needed.
Additionally, in "D" mode it will downshift going down a hill if the speed increases even a little above cruise setpoint, but in "S" mode manual it will not down shift unless you do it.
2012 FF Ti HB Sonic Blue, Built 5/7/12, 401A + Parking Technology Package and MFT w/NAV 3.0.2 -> 3.2.2 -> 3.5.1 -> 3.6.2