An xe is a whole different animal than the old grinds,they have a very agrressive lobe profile with a smooth closing so they are designed to be as close to roller type cam as you can get with a hydraulic.They also build cylinder psi and improve idle quality which is why they seem a little less rompy for a given duration,but they will out perform the older straight grinds hands down.Ive used alot of these and have alot of friends using them as well and If your really looking for max performance on the street/strip they are really hard to beat.