A little bit, they can be heavy but not too much. If you thought the reason behind this is the better CPU and GPU then you are partially right. But there are yet other factors to consider like the cooling. While the GPU does it jobs laptops tend to heat up which must be controlled by cooling fans. Hence the incorporating of better airflow and cooling technology adds to the weight. Moreover, the inclusion of better battery power requires weight. And last but not least is the increasing number of different types of ports to a gaming computer adds to the weight.