I wouldn't use dimpled balls with metal or composite "Gamer" bats. With wood they are fine. I only used dimpled balls, in my backyard cage, when it was real wet out or with snow on the ground! They are just too hard for cold weather use outdoors anyway.
I like the special batting machine leather balls (Jugs, or many others to choose from these days) as they, with their reinforced stitching, wear longer. I have used the same bucket of sixty for 3 or 4 years!
We have a Jugs Curve ball machine that is rarely used except for specific practice on sliders. Other than that, my 60yr. old elbow throws to him from about 20ft out (behind a very L-Screen, "dart-throws" I call it) where I can sit on my bucket, hit my spots while replicating 90mph reaction times.
If you aren't comfortable or can't throw well any longer then the Machine can be justified and order the machine balls for long life.