There's new technology that I've not tried, but have discounted as having very little benefit for me and would cost too much to upgrade. This includes tubeless, disc brakes, carbon fibre frames,
Technology which I have tried, but not convinced in benefits are
External bearing BB's - have gone back to square taper.
Gears for time trials - after a few seasons of riding both gears and fixed, have ditched the gears and just ride fixed. The difference between the two set ups was negligible.
Carbon tri spoke front wheel - lovely wheel, but so difficult to handle in cross winds, so have gone back to a "normal" front wheel.