Refractors mounted on tripods can be comfortable to use while sitting in a chair if the object you are viewing is not near the horizon or zenith. If the star you want to watch is at zenith, you will have to get on your knees and even contort yourself to look up sideways. If the object is near the horizon, you will have to stand, bend, or adjust your tripod to sit. Reflectors which have their eyepieces toward the front of the telescope make looking up easy, as long as the telescope is of similar length to the observer's height. If the scope is huge, an observer will have to use a stool or ladder to view.
Smaller scopes require kneeling or bending over to view.
SCTs position the lens at the end of the scope, but because the tubes are short, the eyepieces are generally higher off the ground. Like refractors, the diagonals can be turned to help with viewing. Stability of Viewing One of the most important functions of the mount is to keep the image stabile while you view through eyepiece. The telescope will vibrate under weak mounts, especially during focusing, wind or when you touch the telescope. A stable mount will allow for easy focusing or repositioning of the telescope without making you wait for the vibrations to settle down.