We installed the Leviton unit and also use additional surge protection. Also our audio ecosystem is on a dedicated circuit with additional filtration and grounding.
Why whole house surge protectors are not enough
TL;DR:
One measure of a surge protector is the clamping voltage. That is, at what voltage does the surge protector actually start to work. Whole house surge protectors are limited to no less than ~ 600 Volts (instantaneous) between a leg and neutral or ground. That’s up to 1,200V if symmetrical.
The best surge protecting strips and conditioners clamp below 200 Volts.
Please keep this in mind when deciding whether or not to use surge protectors at your PC, stereo, TV, etc. in addition to a whole house unit.
I wrote more about this here:
https://inatinear.blogspot.com/2021/09/time-for-new-surge-suppression.html
No manufacturer of whole house surge protection claims that their devices alone are enough for sensitive electronics when you check the fine print.