The rears take the abuse and will typically begin failure by leaking. They will eventually lock up if you don't replace when leaking. I did three pair of rears in 208,000 miles on my 2010.
It is said that these can be replaced individually. For instance one is leaking the other is dry. I don't understand the finer points of how Magnarides work, but I figured the other would fail eventually anyway, so I replaced them in pairs.
I never replaced the front shocks. They did not leak and the ride was still the same. The Magnarides produce the best overall ride I have ever had in any car, period. Not to mention track time.
I have factory Magnarides on my 2011 GMC Yukon. I found this out when the air part of the rear shocks began to leak. The shocks were fine otherwise at 175,000 miles. I kept wondering why my shocks never needed replacing.
I have an updated set of Magnarides on my 2018 Z07. They are adjustable for driving conditions. There is an Eco mode (whatever this means), a Tour mode, a Sport mode, and a Track mode. I was driving mine in the sport mode. Five bent factory wheels later I switched to Tour. I should have been on Tour the entire time. The Tour mode is much more forgiving in the City. The City is hell on Sport. I still run Sport on the highway, along with my new forged wheels..