When setup properly, a 3D plane can go fast, but again, it is not the best thing. I had a Seagull Harrier 90 with an Evolution 100 that would handle full throttle runs, but I could tell that the plane didn't like it too much. Use servos that have a high torque rating, and give them good mechanical advantage. Make sure the linkages have no slop, and make sure they DON'T FLEX. Use beefy hardware, don't skimp in this area. Also, make sure the servo's aren't sloppy cause then, you can't go fast. Use reduced throws and different props like aussiesteve said.

Your Twist won't go fast, the airfoil is too thick. Pick a plane with a thinner wing. But I gotta say, a 3D plane that can go fast is pretty cool. Hearing the 16x4W prop-rip on the Harrier while doing a high speed pass isn't something you see everyday. Also, the plane would give plenty of warning when I oversped. I would hear a WOH-WOH-WOH-WOH-WOH sound and I sould slow down. I never pushed it to the BUZZZZ-Z-Z-Z-zzz [BOOM]. That's too fast. The peanut gallery thinks I'm insane.

Oh yea, if you crap out money, get Bill Hempel's 50% Edge 540. It's fast, and, according to Bill, it can handle full throttle downlines. There's cool videos here:
http://billhempel.com/newsite/pages/videos.html