I have run threw more cassettes that I can remember, ultegra has done well for training and so long as regular chain replacement is done they last 3 to 4 chains.
Lower end cassettes wear quicker and I tend only get 3 chains out of them.
I don’t ride much with dura ace cassettes, I doubt that the cassette would last longer then ultegra. If it did then it would need to wear 2x slower then ultegra to make it financially justifiable for training.
For racing, the extra weight loss is easily justified considering how difficult (costly) it is to reduce weight on wheels. Rotational weight is key during races with lots of spin ups.
Seats are a very personal preference. Sense I am allergic to the pads in shorts I tend to prefer a softer seat.
Considering that I am heavy on brakes, I should try out more brake systems. Ultegra does well in all conditions, wet, dry, dusty, out right mountain bike muddy and cold, salty with mud mixed in.
Tiagra fairs close to Ultegra in conditions expect they are more softer. They work fine on my commuter.
Over all the Giant Tcr compact frames are a fairly inexpensive platform to build your bike on. Personally have found them not to be the stiffest frame but that has not changed my results in any significant way. Aero dynamics is where improvement could likely be made.
Ultegra, Dura Ace shifters fair well for training and racing. What tends to do them in is dust which gets into the shifters and or spring breaks in side. The Dura Ace are some what lighter but at this moment have not noticed any difference in Durability.
So I have far been using Shimano cables and housing, they last the usual year though could replace them more often. I only recently started trying other brands and the http://www.yokozunausa.com Cables look promising, putting it on the todo list.
I am still looking for a good handle bar tape that feels good. My preference is cork but last few brands have not faired so well.
A good fitting helmet can save your life, the giro helmet is what fits me fine for every day road or mountain bike riding. For time trailing the Louis Garneau Rocket air with the clear visor has worked well for me. http://www.louisgarneau.com/ca-en/products/305554/AeroTT
My favorite bottles so far are the www.tacx.com water bottles. I taste the least amount of plastic in the water and the bottle does not break down as quick as other brands. So far the cap has stayed on good even when dropped.
Wheels built with
- mavic open pro rims
- Ultegra Hub
- DT Swiss double butted spokes
A reliable training wheel, good for 15,000 km so long as maintenance is kept up. For some 30,000 km depending on riding style.