OVERALL: It is a good machine for the money. It is well constructed and functions reliably. It is more sturdy than the cheaper models and to get any significant improvement in features & performance (in other models) would cost nearly double.
I purchased it with the oscillator and consider that an essential component. While there is some variance in the speed (and therefore the trajectory) of the ball, coming from the same angle every time would only be useful for some drills. With the oscillator, it can be configured to keep a doubles pair busy or a single extremely busy.
It is easy to setup and configure for a wide variety of training/practice options. Angle, ball speed and feed speed all have sufficient adjustment to allow a wide range of scenarios.
There is NO documentation included with the machine. There isn't even a quick-start guide or sheet. Everything is online. There is, however, a HUGE laminated card (takes up the entire top of the box) that is mostly promotional about why you should buy the Slinger. I already DID buy one, so why the poster ? It has about 8.5"x11" of diagrams of "suggested" settings that could have been included as a page in the missing quick start guide.
While the owners/operating manual (pdf) is quite Avant Garde, the white lettering on black background does NOT print well and consumes far to much toner/ink.
The remote is somewhat flimsy and the buttons tend to stick in the housing causing them to trigger…