Inside or Outside Cat?

I live in the country and my cats go wherever they want. They always come back, and its very rare for any of them to disappear for more than a day. Some of my cats don't like going outside, some go outside all the time. The ones that do go outside tend to hang around the house. Most of my cats are strays that we found on our doorstep. Some of the strays find the indoor life to be very exciting or relaxing and don't want to go outside. Some of them still like the outdoors knowing they can hunt mice or chipmunks. Since we live in the country I suppose we have the freedom to let our cats decide whether they like the indoors, the outdoors, or both. When they want to go outside they sit by the door and wait. If they want to come inside they sit by the door and wait again. Since we have a transparent sliding door it is easy for us to let them in and out.