I have unlocked it (I like to use if for speed) but wouldn't put additional skill points on it either. I did in beta and, like the OP said, it really wasnt of much more benefit as far as damaging enemy ships were concerned (and, half the time, I completely missed the ship I was trying to ram anyway, because you can't turn once you've clicked on it until the timer runs out.
).
Unfortunately, there are more than a few skills where you don't gain much from additional skill points.
As far as ramming speed in the Boss Battle, I only recall hearing of one person that used it successfully there.