Downtube vs. Integrated.

Whats advantages of each? While reading the component list of the Allez Double Steel, I read that the bike has "reliable" downtube shifters. Are they really more reliable than integrated (or brifters?- still a little lax on the roadie lingo).

I read in another post on bike forums via archives, that a disadvantage to DT shifters is that its harder to shift while still in motion, and harder to shift fluidly since you have to reach down and shift as opposed to keeping form and tapping a lever.

If you had a bike, such as the Allez double steel, that had DT Shifters, would you throw on Integrated shifters and use DT boss adapters for it?

Is integrated shifters "less reliable" since there are more moving parts to contend with (..thats an assumption. Sorry if im wrong).

Thanks for the help guys.