My current ride has Ultegra 9 speed on it, which has been perfectly functional. Recently, I've come across a 'never been used' 9 speed Dura Ace group. I'm so tempted to buy it, given it's about half of what it should cost. However, I've been looking at motorcycles again and am begining to suspect that I may be looking at the Dura Ace stuff for the wrong reasons. Is there a significant enough performance difference to justify the investment, or am I seeking the "top of the line" for some other reason? Help. I can't seem to make a decision on this one!