Homebrewing: Using syrups/honey/sugars

I've been doing a little more reading and studying on adding honey, cane syrup, or sugars like piloncillo to beer since I made a porter with Steens and piloncillo. (a little late once it's made, I know)

For this batch, I added them at the beginning of the boil. When racking, I couldn't pick up much of the cane syrup falvor, though it was certainly sweet still. Next time I make this I am going to wait until the end of the boil (5 minutes or so left) to add the syrup and sugar and see if that makes a difference in the final taste. Seems like this is what I see most commonly suggested for adding honey so you don't boil out the delicate honey flavor.

what is your experience and preference in adding syrup or honey to your brews?