now days i cut them off since i never had fast rooting and leafing out with tip cuttings. there is certain hormone that prevents tip cuttings from rooting fast. the tip bud suppresses something.. i think pete s. had a post.i forget what that is. i'm sure everyone's experience is different. however, if i root 10 cuttings with tips only 1 or 2 will response in reasonable time. i think someone put it nicely "rooting is race against time". sooner you root them, and sooner they are in 1 gal and outside, they have better chance of survival.
good example is my two Maltese Beauty cuttings. one was tip cutting, and another was not. the non-tip cutting is now in the 1 gal and the roots have reached the drain hole. the other, tip cutting ddin't response to anything until about a month ago i remove the tip. i hate taking tips off when they are in the cup. it didn't show any roots at that time.
i noticed bud breaking about a week or two ago, and roots pushing to the edge of the cup. it was about 2 months slower than the non-tip cutting. then there is USDA/UCD Ischia Black. they sent one long cutting. i cut that in two. the bottom cutting rooted fine and i put it into a cup. the top cutting with tip still on it didn't do much of anything and died. it did put on a tiny leaf that was so pretty..
but then there is another varieties the doesn't seem to have this issue. Kathleen's Black roots no matter what for me.
so to improve my chances, i remove all the tips now days. they root faster for me this way.
of course, final choice is up to you. if it works for you with tip still on, why not? :)