I personally dont perform using a close-up mat in restaurant work, and my arguement for this has been brought up by reading loads of magic thoery...
If you want to get your audience to connect with your magic on a more than physical "wow" level, more on an emotional level, they must be involved in the magic, and believe that it is not just a trick, but that it is somewhat real. Now, this may still mean that you could still use a mat, but using a mat seems, for me at least, that it is giving a certain "I've practiced these tricks hundreds of times" feeling to the performance, unlike a 'real magic' feel. Now please dont go saying that I said not to use close-up mats, i am just stating my personal opinion. If you want to be more intimate with your audiences, it is my suggestion you dont use a close-up mat. But like i said, this is my suggestion, and nothing more.