I spent a LOT of time last winter with my son throwing baseballs to him from behind an L screen - FROM 25 - 30 FEET AWAY! Now, that's not for everyone, because you had better have quick reflexes! He's a pretty big boy, 6'2", 195# and hits a baseball VERY hard. To reduce the fear factor, a catcher's mask would probably help. I also worked with DD, who's playing college ball. Try that for an eye-opener. You find out just how hard a softball comes off a Rocket Tech bat!
Here's my reasoning for this insanity. Throwing from a much closer distance allows you to throw much easier, with superior accuracy and less arm fatigue. You can place the throw exactly where you want, and change speeds at will. By throwing from such a close distance, you can throw at just 30 mph, but it looks like 60 mph to the batter. You can throw any variety of "off-speed" pitches. By using a casual wind-up, (obviously overhand for baseball, underhand for softball), the batter can also work on timing, because they're seeing an actual pitching motion. I think it's nearly impossible to do quality work on timing (stride, load, etc.) with a machine.
Pitching machines (and cage machines) throw one speed, have one release point (usually too high for fastpitch), and throw at one spot, forcing the batter to change positions to simulate different pitch locations. You can change speeds and location, but it takes a little set-up time and a few test pitches to get what you want.
The son was having trouble hitting drops, curves, and "away" pitches. Because of his height, he got a LOT of off-speed, away pitches. All I can say is that after working like this - with VERY LITTLE use of a machine, the results were phenomenal. There's more to it than just that - we used Right View and some Steve Englishbey methods too.
90% of our work involved tee work, soft toss, and hitting "L-screen" pitches, combined with Right View video analysis. About the only time we used a machine was for fine tuning, to see if he was driving the ball consistently (avoiding pop-ups and grounders). A LOT of work, but you get out of it what you put into it.