Hi - when I was teaching I was often asked what's more important speed or accuracy?  Well both are going to have an impact on your score, when you're doing a typing speed test, so its important to consider both elements.  However, its very easy to get carried away with pushing your speed.  But if accuracy suffers, this will in turn, have an impact on your speed. 

Have a look at my web page - Speed Vs Accuracy which expands on my thoughts further......

Sally