I'm definitely not one of those wine writer-types who dismisses hybrid grapes. I've had some terrific wines made from Vidal. Have enjoyed several different styles of Vignoles. And, I even like Seyval Blanc when it's done well. Some winemakers treat Seyval a bit too much like chardonnay for my liking, aging it in oak, which just isn't a good idea. Others leave a significant amount of residual sugar in the finished wine, trying to appeal to the white zinfandel set. Jeff Dencenburg, winemaker at McGregor, did a little of both with this McGregor Vineyard 2007 "Emery Vineyards" Seyval Blanc ($16),…