EU constitution is far from the finished article
It modifies existing treaties towards a federal philosophy incorporating changes in how national sovereignty is to be applied. The term 'pooling of sovereignty' has raised eyebrows, not least in relation to foreign policy where there's stark division.
The clarity of decision-making within the EU is in doubt as a result of vague articles and provisions. Article 7 deals with the principle of conferred powers, given to the EU as a separate legal entity by the individual states; the hot issue of federalism is manifest in the document across a number of lines.