I am thinking of changing my chainset - mine is currently a 3/4 years old tiagra set. I am looking at the 105 5800 as the colour matches my bike more than the grey of tiagra. However before i throw £60-70 at it, would i see any performance upgrades from the new one or would it only be aesthetic? Is the difference even noticeable? If it isn't i think i'll leave the bike as it is.