A Dremel 4000 is a good option for cutting drywall. To cut drywall with a Dremel we use the #565 Multi-Purpouse Cutting Kit or the #562 Tile Cutting Bit.
A Dremel is actually pretty good at cutting drywall. If you do not have a drywall saw or rotary saw to cut drywall, then a Dremel will be able to do the same job. When remodeling or building our homes, we most likely have to cut some Drywall.