I second the notion that the quality and performance of avocados is highly influenced by location, and what isn't very good in one part of the country may be much better (or worse) somewhere else. I have a good-sized Wilma (clone of Brazos Belle) and it performs differently than the same cultivar in Florida. Duke avocados grown in Tucson during the mid-40s were reportedly larger and better quality than those grown in Southern California. I have an Opal/Lila that is very low and slow-growing while the same trees elsewhere are vigorous and upright. It's really hard to generalize, but a local nursery owner says his two Mexicola Grande trees produce excellent-tasting fruit (I haven't tasted them). My neighbor likes his Zutanos (I haven't tasted them either), and my Wilmas taste good when they taste good--but often they ripen unevenly or fail to ripen at all, and of course, then they aren't worth eating (just like every other unripe avocado). A grower in Texas likes the green-skinned varieties best, and says Poncho is his favorite among the trees in his yard. A guy in Florida is very enthusiastic about Del Rio (which as near as I can tell is the same as Pryor/Fantastic). Everything I've read about Duke sounds good. I agree with Spaugh that if you don't need the cold hardiness, then you have better choices, but If you just want to give Mexican varieties a try, why not? Since they are so variable, my hope is to graft a bunch of different cold hardy varieties onto two or three trees so I can compare them and find out what works best here, without dedicating the whole yard to them.