I've got a core of mags that are upgraded with Magpul followers, Ranger plates and Wolff springs. These are ultra reliable. They are my SHTF mags, if you will. Most of the other mags are range mags with original springs and green followers. If they show even the slightest sign of FTF or tilt, the spring and follower are pulled and Magpul/Wolff are installed in their place. I have slowly built up about 15 mags in this configuration and will continue to do so, as needed.
IMO, if you are doing some type of active shooting with reloading, and a partially loaded mag has a chance of being dropped or something like that, that's where you would see the benefit of mag upgrades. If you are a square range, bench bound shooter, you probably will never see or need to see the benefit of these followers.