Paddle drums come in a variety of sizes. The larger the head, the deeper the sound (and the heavier the instrument). I love the deep sound of the 14" drum, but find it can sometimes be too heavy for my children to hold for very long, so I usually use my 2 - 8" drums and 2 - 10" drums. The best thing about paddle drums is that they have a handle and can be used in ways that standard drums cannot.
One of the activities I like to do to stimulate coordination and motor skills is to march while playing the paddle drum. I encourage the child I am working with to hold the paddle drum with their non-dominant hand and the mallet with their dominant hand. Then, as I play a good recorded marching song (Yankee Doodle on my keyboard works quite well - good tempo and it's a familiar tune) and encourage the child the hit the drum with the mallet while marching in a circle around the room. If the child can accomplish this task on his own, I will play my own paddle drum and march along. Otherwise I will hold the drum while the child plays, or stand behind the child holding the drum and holding their wrist while assisting in playing the drum and moving along.
The music assists in the motor planning of marching and playing the drum.
The Remo paddle drums come in a variety of packages, include mallets and even include a ball that can be bounced on the head of the drum! Another favorite of my clients has been the Lollipop Paddle Drum. I use the Lollipop as a reward for participation in other activities as it can be visually distracting to some kiddos - as you can probably see!