The good thing about magnesium risers - forged magnesium, like your MagnaTec - is the riser is heavier and stronger. Good mass weight for stability. Excellent strength to avoid flex and bending, also creating additional stability. It will withstand pressures that would bend a more expensive riser machined out of aluminum billet.
The structure of the forged metal itself has a vibration damping quality, unlike machined billet risers. Take a bare riser of each type and drop them on a concrete floor. Machined aluminum risers vibrate and ring like a bell without external damping doodads. They go CLANG-G-G-ng-g... where a forged riser just goes Clank. So, the forged riser makes for a quieter bow with less shock and vibration. Start out with a quieter riser with less vibration and then add the extra damping doodads, and what do you have....
That bit about strength most definitely DOES NOT apply to straight cast risers though. the riser has to be forged to get that benefit.
The bad thing about the magnesium risers is, they are heavier. After a long day, you feel like you're toting a chunk of lead.
Overall, I strongly prefer a forged magnesium riser over the machined aluminum. But they've done a whale of a job at marketing the machined riser, and it's hard to find anything but machined any more.
magnesium vs. aluminum risers
