Drilled 10 4.25" diameter holes in my retaining wall at depth of 9" each.
There were not many instructions to put it together, fortunately, it didn't really need it. They ship it a certain way, you have to take it slightly apart and put it back together the right way. The feet go on the "front" of the pedestal. The feet were essentially useless for me (though they would be great in most other scenarios).
It would have been a great little addition if they had included the $4.00 garden hose adapter you need for the water. Additionally, a 1 1/4 to 5/8 attachment would have been great.
I also wasn't sure what two of the pieces were for (they looked sort of like fuses, but I have no idea what they are).
Aside from all of that, it was GREAT! I have NEVER drilled a core out in my life and I got 10 with this one core bit and core drill and they were exceptional. I DID predrill, though. I used a concrete bit in my hammer drill where I wanted the hole and a "throw away" 4.25" hole saw to score the blocks where I wanted the holes. It helped me line things up perfectly.
Go SLOW at first. The big will catch on the ground if you go too quickly. So just take your time. Once you get a bit deeper into the core, you can push it a bit faster because the bit has the support from the walls. But until you get down a bit, it'll catch and (if you're not standing on the drill plate on the back) throw you around.
Make sure to TURN OFF the machine before pushing the reset button. Always restart from scratch. Turn everything off, reset position, buttons, etc. Then start.
5 Stars because it did exactly what I needed it to do without any additional needs, saved thousands of dollars, and looks like it'd be able to do it for a lot longer.
Thomas 
