Project Orion was perfect even a master piece, It helped me correct my flaws and learn whole lot of new things about java, minecraft and programming.
It also teaches you about efficiency so the work you have to get done, gets done faster.
To sum up, It is really got for people that are beginning to learn and also for people that already have knowledge because it tries to explain everything from the begginging (the thing that other courses does not offer imo).