I have had both, Both good markers.
Speed is not as light as the new Shocker.
I personally like the new Shocker better, I like the trigger better! But that's only my feeling.
You should do as everyone says and have a go of both, and remember that how you set the air system and what type of hopper you use, all affect the "feel" of the marker.
I sold my Speed, but keeping the Shocker for a long time to come. Well at least until I can get my hands on a Viking!