Some restaurants/bars have a decent well. Most don't. Many well (and even not well) tequila is a recipe for an unpleasant next morning, no matter how disguised it may be in your drink - in fact, mixing it until you can taste no more in a soup of sweet goo is only going to make the head hurt more. Vodka y Rum, the 2 most likely things I won't call in a simple mixed drink.