Are you mainly using a helmet-mount? Unless you follow right behind someone, the helmet mount doesn't show the perspective of how fast you are going very well. You gotta have a moving object to focus on in order to represent realistic speed. For that purpose if you're just riding by yourself, a pole-cam does a much better job of showing that speed.
I'm no pro with editing software but I've been using Sony Movie Studio 12 Platinum and have been liking it. It's a lot more technical than WMM, but you can figure it out fairly easy by just monkeying with it for a while.
PowderHound and TreeNinja