Originally Posted by shakeNbake
Wow, that alot of question.
I'll start with:
Yes there are difference between them. But because of the law of diminishing returns, the higher you get on the price the less "improvement" you will see.
The others should take over.
+1
One of the truest statements I've heard. Most riders can achieve their goals with a nice Shimano 105 or Campy Veloce equiped bike. Those are the ultimate bang for the buck groups out today. Yes there are lighter groups. You have to measure in grams not ounce to tell the difference though.
IMO, you can get a great riding bike for $1000 to $1200 If you buy online you can even pick up an Ultegra bike for that money. Good luck on your choice whatever it is.
Tim