I use syrup in the spring to strengthen a weakened colony, and when starting new packages. It helps tremendously by giving them a boost before the pollen flow and local bloom. But I'm leary of anything thats not natural, for myself and my bees. Lets face it, sugar is intensley processed - very far removed from its natural state. We're fooling ourselves thinking there a little if any side effects on ourselves, let alone the bees. See what the average kid looks like today and how much sugar and high fructose corn syrup their diets contain?
One of the reasons I keep bees is that it brings me back to a more environmental approach to life. I unplug, spend more time outdoors, I interact with a creature that still witholds its secrets, which causs me to see so much more of the natural world around me. I follow a tradition that's thousands of years old, and I use honey in place of any white sugar consumption in my foods. Lots of studies show that our immune systems get weakened by processed foods, so why expect the bees to be unaffected? But I could never feed them my honey stores!! That would really hurt me!