How fast should a website be? The answer: As fast as possible. But if you’re looking for an exact number, try to keep your load times under 3 seconds for the best results. Here’s an infographic about website speed you might like.
The greatest problem with the idea of responsive designs is in the fact that it has tough competitors in trends such as adaptive design or even mobile first design. Both of these trends, although great in their narrow fields have some serious downsides that a responsive web design more than makes up for.