As skill points are the best thing about leveling (in my opinion), it's counterproductive to spend lots of skill points to get a few more levels.

And it's a huge skill point loss before you recoup them through levels. Spending points on Learning weakens your characters early in the game (when they can face real challenges) in order to (supposedly) make them a bit tougher in the endgame (when they really don't need it).

And note that levels are proportional to the square root of experience, so an impressive sounding bonus to XP doesn't give you a correspondingly impressive bonus to levels.

So I always buy basic Learning but never put skill points into it. (Though depending on what "theme" of game I'm trying to play, I may edit in ranks of Learning.)