Another thing is, as you get used to the board, you'll be able to better teach yourself how to avoid bottoming out, and then you'll be able to do higher speeds.
Certain types of keyboards feel good but are slow, and others feel terrible but are fast. All depends on what you're used to. As I do very little transcription, I find that while I can usually do 100 WPM, I can't mentally keep up with that typing rate, so it's all a moot point.