Full caps are better in theory but in reality they offer as many problems as they solve. Getting the nape to look natural, feel comfortable and even stick down well, is something that many people struggle with. Then there are the temple points. I've rarely seen natural looking temple points on a full cap. Paul here on TL does a great job but many will struggle to match his ability to pull it off. If you have good side and back hair a topper is far better for comfort and ease of wearing. But if you are too thin for that you can still get a good looking full cap but don't expect it to be easy.