I have a 2004 Giant TCR Comp Team frame (it is great!). My components are not a match for the frame - basically I have Shimano Ultegra (with a Dura-Ace rear derailleur). I've upgraded a few things and am now considering moving up to full Dura-Ace components. Cost would be hefty in the $1,000+ range ... Any perspective on what improvements I would notice? How about weight benefits. Thanks.