I also used keybr when I was first learning. I found that I capped out pretty quickly there though, easily getting 100% for all the letters without going particularly fast and, as you mentioned, there's not much for punctuation and numbers. After I got good at keybr I moved on to gtypist and boy what a world of difference. Gtypist is significantly less forgiving and I still do poorly at it even after typing on the daily for years. It helped a lot for the time I was able to stick with it.