there are certain doctors I speed up very fast and believe it or not I actually understand them better. Others I slow down and have the same affect.
Not to be insulting but have you tried this, do you have easy access to the speed?
Best of luck and you may not believe it but sometimes you can pick up more skills with the more difficult dictators...I started that way with a supervisor (it is funny now but was not then) who gave me every difficult (terrible) dictator for an entire hospital, and it only made me better...