Tim:
It all depends....
What are your needs?
The X-flow offers bags of character, and in a high state of tune is a great peformer, though it will be stressed, and shorter lived than the more modern zetec. The X-flow is classic and its bark warms your soul.
The zetec with carbs, new cams, and 3D ignition offers more horsepower, lower maintainance, and at 200 hp is bomb proof. If you need to go the distance with little time for feddling, it may be the better choice.
Either way will bring you miles of smiles!
Michael
X-flow equipt Yankee