Originally Posted by
halfspeed
To meet a price point.
Why? If the carbon frame is lighter and/or rides better, the components can be upgraded later.
I think the OP was trying to stay within a budget. Upgrading from full Tiagra to full 105 would cost at least $200-300, not including labor. My point is if the carbon is significantly lighter then get the carbon and deal with the tiagra. If the weights are about the same (like within a pound or two) then get the alluminum with the better components that won't need to upgraded.