While those interested in Deep Sky Objects such as galaxies and nebular would want the light gather power of the larger Newtonian. This size scope will capture numerous galaxies and nebular with reasonable detail. The length of the scope tube is determined by the primary mirrors focal length. Lenses or mirrors can be made with long or short focal lengths. Long lengths give higher magnification while short lengths give brighter images and are preferred for deep sky use.
Photographers prefer the shorter focal lengths and everyone loves a compact tube for portability.
Short focal lengths are more difficult to manufacture however so optical quality then becomes a concern. The magnification is determined by the focal length of the scope divided by the focal length of the eyepiece. An eyepiece with a 0.5 inch focal length would yield 96 magnification with any 48 inch scope. That's closed to 10 times that of your standard 10X50 binoculars.