Personally I am a fan of hitting machine and out of hand. I believe the hitting machine is great for grooving your swing working on your mechanics while gaining confidence. In the out of hand cage I am a fan of pitchers pitching to hitters. Bring the portable mound and an L screen right in the cage. Have catchers catch and now you are working on three phases of the game in one cage. Then along the side of the cage or into that tarp do your tee work and flips. I personally hate working with any kind of ball thats not a regular size and weight. The safety balls they make that are regulation size and weight are fine. But wiffle balls I hate. Just not a realistic look for batter. Then there is always some space left over for throwing and ground balls. By doing your work in stat Ions nobody is standing around or at worst you have partners. I think standing around is the worst element of any practice indoor or outdoor.