Like anything else, the sizing you are looking at for HDs can affect performance depending on what your application and read/write requirements/habits are. Its inaccurate to state "performance problems" as a global issue as "performance" means different things to different customers.
Consult with your salesperson and thier SE..they will be glad to help you make the best decision to match your specific environment, or follow this thread..im sure we'll get into a healthy debate on this. *grin*
Cheers!