Switch mode BEC's can usually handle a higher input voltage as they generate less heat. However, they are still limited, in the voltage they can handle, by the internal components.

Before you make the decision to jump into a switch mode BEC, there is a drawback. Linear BEC's generate almost no RF interference. Switch mode BEC's (specially cheap ones) can generate RF interference to the point that it can effect radio range and performance.

These problems can be limited by installing the BEC away from the reciever antenna and by not crossing any servo leads around it. Some are much better than others, so if you were to decide to go this route, be sure and reasearch you purchase. Get recommendations from other flyers that use them......If you cannot find any reviews, online, or cannot find anyone that has experience with a product, it's probably best to avoid it.