When you are preparing a mexican-style dish, this marinade can be used for any type of meat, poultry, fish, or seafood. The lime and cilantro flavor blend well together and is not too overpowering. While it has some spice, you can adjust the heat level by using more or less of the ancho chile powder. While many people love cilantro, it has its detractors, as well. Check with your guests about whether to include it or not. Marinades such as this one tenderize and enhance flavor. An acid is used (in this case, white vinegar, and lime juice) to help break down tougher tissues. But left for too long, the meat or seafood can become overly tenderized and end up mushy. As well, this tenderizing action allows the tissues to bring in more fluid, so it won't dry out as rapidly when grilled. The salt, spices, and herbs add flavor. You should marinate in a container made of glass or food-grade plastic (including sealable plastic bags). Don't marinate in a metal container as the acid can act on it and it can result in off-flavors as well as possibly etching the container.