In 10.1.x, the magnified Dock is a CPU WASTER. It stresses Quartz/Windows Manager to the max to create this bling-bling effect. It's really meant to grab people's attention or to store a large amount of apps. But for the average user, magnification is bad.
If you do like this effect no matter what, wait for QE and it won't take an CPU power and it will be faster (providing you are QE supported).
Otherwise, it'll slow your system way down in 10.1.x and 10.0.x and can even make your applications launch slower. Please don't tell me you make the dock bounce too? 🙂