For example, say you were in your 40's and did three more levels of learning, 8, 9 and 10. That would cost you 27 points, or three levels worth of skill points at that level. That would give you an additional 9 percent experience bonus. So you'd think that you'd get a little less than one extra level for about every 11 levels after that. Except you don't. Because the amount of experience required for each level goes up so rapidly, by the time you hit level 80 (for example) by my calculations you would only have gained a little less than 2 additional levels and still wouldn't have earned back those 27 points.

The extra levels might be worth it, I guess, but it just doesn't seem all that worth it to me, especially since the skill points are much more valuable, relatively speaking, at lower levels. And, if I remember correctly, the experience bonus doesn't apply to experience gained from completing quests, so it would end up being even less than that.

Hope that clarifies.