In my opinion, the dagger boards alone are not the reason to throw out the 18 - heck, even a Snark has a dagger board. It's more an issue of the overall complexity of the boat, the additional items to rig (properly) and the increased power.

The advatages that the 18 has over the 14 and 16 for a beginner (again, in my opinion) are the increased floatation (particularly in the bows) and the ability to furl the jib in high wind.

That said, the evolution towards the Wave and the Getaway makes them better entry level cats than the 14, 16, or 18 for sure. The Wave and Getaway take all the simplicities of the 14 & 16 (no daggers, simple rigging, light mast) plus the added flotation and furler from the 18 and stick them on a super durable hull that's much better suited for a beginner.

sm