About the same size as the cabin of an executive jet and as darkly intime as Antonio Banderas' eyes, this dinners-only slice of high dining has been enjoyed for 35 years by luxe Lauderdale. And it doesn't need to raise its voice to declare its utter suitability for proposals of any kind. You, however, may scream in delight over the 23-out-of-30 2004 Zagat rating, the wrinkle-erasing lighting, and the suggestive lapping of the waters drifting by your table overlooking the quiet canal. It's a high-priced-and-savagely-worth-it spread. Taken over by new owners a year ago from the Romano family that moved it from Brooklyn in 1970, La Tavernetta has a menu that leans more toward the tastes and colors of northern rather than southern Italy. And the wine list has expanded its breadth and depth (ah, those Chiantis!). But nothing else -- not even the easy-to-miss side entrance -- has changed here.