To answer your basic question...
Based on the data from the BB Training Project, a Superior trainer would give you 6% more training and an Exceptional trainer would give you about 10% more training. If you want to talk "pops," a decent estimate would be almost 1 more pop per player per season per level of trainer (assuming you're doing single-position training). But the data that has been collected thus far on this subject is quite noisy, so take that with a grain of salt. So, it's a big investment for a small advantage. But it you use it well, it can be worth it.
I say if you think that sounds like it's worth it to you, go for it. If not, stick with what you got. It'll be sufficient for a long time.
And when you buy staff, my advice is to buy higher salary guys that you can pick up for less than $10k in signing bonus. And then turn them over pretty frequently. Usually you end up with lower over-all costs that way, no matter what level trainer you go with.
Last edited by rhyminsimon at 11/14/2012 12:23:06 AM