Good thing I suck then, no worries about component level.
Curious which parts do you think would break, RD? I would imagine shifting under load will put a fair amount of stress on it. Besides Machette wants to do tri, I think aero is more of an issue there then durability or weight.
First, Ill PM back everyone who asked me about good VS bad carbon frames ASAP.
Second,
Shimano shifters aren't rebuild-able like Campy's. If they break you have to get new ones since the brake/shift mechanism is one in the same.
The shifters will break because they can't take the abuse of being quickly shifted hard and often.
The rear der simply isnt quick or accurate relative to 105/Utl/DA and the spring is weak. Yes they are very heavy but unsprung wieght on a bike doesnt really matter unless you're a blood doping 117 lb Italian world champ.
What makes a HUGE difference is the rotating mass like wheels/cranks. those 100 grams and better hubs are absolutely noticeable.
Ult/DA perform the same but DA is 420 grm lighter...no big deal. No need to get DA other than bling. They are more precise than 105's though.
Tri shifters all work well, so you can get 105 thumb shifter and a DA rear DA and you'll be golden in terms of performance. 105 front Der is fine since it only moves in two positions.
I can have any bike build I want and I choose to train/everyday ride a relatively heave but SUPER stiff frame with ultegra shifters/ultegra front Der/DA rear Der/DA casette with ksyrium SL wheels (bullet proof under 210 lbs of pure man)
My race bike build is very different but to sensitive ('spensive) to ride every day on real roads.
I know that what I wrote isnt 100% clear but Im super rushed these days.
Will get back to PM's once I have the time to answer them properly.
...and dude with CX wheel question, dont buy anything till I answer you
porker, yes, I know. 
