It really depends on your own body AND primary usage conditions. For myself I spend most of my day seated and working on a computer so:
Personal Input Conditions: Sudden and very large volume voids (400-450 ml.), 3-4 times throughout a working day (possibly 5 depending on Diet Coke overindulgence)
Usage Conditions: Primarily seated for long stretches of time
While I might be able to get two voids from a Lite in a standing position, it is impossible in a seated position. Don't get me wrong, Lites are a great product and are a standard tool in my toolbox. However, they are relegated to around the house wear for me or very short duration trips if I leave dry. That little extra absorbency (as well as the difference in build) between NS Lites and Supremes makes a world of difference for me and my own conditions. With NS Lites I would need to change 3-4 times throughout the day at work...not ideal. With NS Supreme I would only need to change once, MAYbe twice.
Now everyone has their own personal ideas of "discretion", and "thinness". For myself I've actually found that MegaMaxes are very thin and discreet while allowing me to go about my daily business without worry of leaks or changing. For their capacity, they are very thin compared to others in its class, especially when dry. That thinness also translates into discretion for me, as well as the plastic being of a much higher quality that Lites there is much less rustle and noise.