I got Llumar Formula One Pinnacle 25% on all sides and rear windshield on my MSM with white interior Model 3, but if I were to do it again I would definitely go darker to 15% or lower.
The white seats and interior accents just reflect too much light IMO. On white interior, it looks more like 35% and not quite what I expected in terms of privacy and esthetics. So if that's important to you, go darker, no hesitations. At some point I might get the front windshield tinted 50% to see if it can darken up a bit, but that might even be wishful thinking...