Just to add my 0.02 €...
When testing CORE on 1.02, we all felt that research felt realistic with 10 slots. Very late in the testing we added some research speed but increased the research penalty for researching ahead of time. This was done to specifically slow down majors (who can afford to research ahead) and speed up minors.
As Hagar stated, we have to review this for 1.04. For example, in 1.02 we cannot accelerate research long after historical time beyond a factor of 1.5. This may be changed in 1.04.
T.