Responsive theme or switch theme??

Hi,

Wondering what the general feeling it when creating sites that cater for mobiles..

Is the preferred method to switch the theme to a mobile theme using something like the themekey module or to use a responsive theme so its the same for both PC's and tablets/mobiles??

Also any recommendations for handling page layouts?? For example, if using panels do you create page layouts for different breakpoints where content no longer fits nicely??

Thanks for any thoughts..