I usually use two or three drops,(it makes your hits more harsh though ,so be careful, one is preety good to begin with)

It gives you wayy more of a body high, and is really a good enhancement. My friend has tried hash, and says it is a nice alternative, but is more of a body high. I love the oil, but i don't always use it.
i'd reccomend keeping it at three drops max, b/c it makes the hits really harsh, on your palate, and that isn't fun, until you get stoned, and then it doesn't hurt at all.
The other good thing about hte oil, is it is easier to use in cooking too.
I could go on for days about the oil, definitely try it man, I haven't had a negative experience yet. Don't try putting the drops on your tongue though. It does nothing ,and jsut wastes the oil. Tastes pretty good though, nice and sweet.