My altis has OEM5 at the back glass and rear side windows, OEM20 at the front side windows and K28 at the windshield.
No problem at night naman. The OEM5 at the back glass is ok even at night because headlights are shining directly naman unlike the side windows so I recommend not going darker than OEM20 for the front sides.
The K28 is noticably lighter than the OEM20. The shade is also browinsh compared to greenish for the OEM series. In my opinion, it really helps to see the front better compared to the OEM20 and the TSER is higher too.
I would have installed K28 at the sides too but natakot lang ako na baka noticeable ang difference ng shade ng side windows and I would have paid full K series price even if OEM5 ang kalahati. I need the darkest shade for the rear passengers kasi nasisilaw ang baby ko when traveling early mornings and late afternoons. Nakacarseat pa naman so it's difficult for her to hide her face from the sunlight.