Simple answer is it is system and person dependant. Get you dealer to let you do an in home demo. I have had a positive result. Others will say not. In the end please your ears as much as your budget will permit. As Danib1 states this subject brings all the (blank) out of the woodwork. Cables in general cables IC's PC's etc are really a "must try" item.
Do power cords make an audible difference?
I recently discovered the inexpensive Pangea AC-9 power cord. It was so inexpensive I decided, just for kicks, to buy one for my sacd player and my integrated amp. I was extremely doubtful I would hear any difference at all. I plugged them in, turned on the system and I was surprised. I immediately invited a non-audiophile over for a listen. She had only heard my system for maybe 30 minutes with the old cords and I asked her if she could hear a difference. After listening to only two tracks she said "it sounds more clear". This is exactly what I had thought. I also noticed the sound stage seemed bigger. Now, it's not A huge difference but it is noticeable to the casual observer, so it is significant, which is more than I hoped for.