Ok,
Given our posting this in the racing forum, I'm assumming you're getting it to race ( and I do know Roberto Heras won the Veulta, using a triple for some stages). Thus, do you really want tot get a triple?
The triple will be slightly heavier, and shift a little less crisply. And unless you're doing some big mountain races, you'll never use the small chain ring.
Particularly with the option of putting on a compact as needed, I would think very hard before buying a bike set up for a triple as a racing bike.