As far as function is concerned, it works like it should. The biggest limitation currently is the drive belts are a little long. After spraying for 45 minutes, the belts will get wet and lose friction. I believe the issue would be fixed with belts that are 1/2 to 1" shorter total length.
I forgot to mention I have the hitch-mounted hauler designed for this sprayer. It fits into a 2" receiver hitch and allows you to haul the sprayer without a trailer.
I bought it used from the original owner a couple years ago. He had it for several years, as I recall. It is not a young machine, by any means. It just hasn't had a lot of use.
I would not compare this against the newer Z-Spray rigs out today. While the construction is pretty good on this unit, the newer units appear to be much more efficient and ergonomic.
I used it to apply pre-emerge and it does great if you discount the belt-slippage.