I just bought one of these splitters and fired it up friday evening. so far I've split over 2.5 cords of wood with it, I have to say it has beaten every expectation I had for it.
Right now if you get the flyer in the mail, there is a coupon to get the splitter for $650, call ahead though, the sales guys told me the splitters are flying out the door, they had one in stock when I got there. Of course I bought the two year warranty for it, another $179, this is Harbor freight after all, and I also had to buy 3 gallons of hydraulic fluid, and a quart of oil, almost another $50. So I really spent $877.89 total.
Assembly was straight forward, though I would warn anybody buying one to have a strong helper to get the ram assembly onto the trailer section, I did it myself, and it took three tries.
The predator engine is fairly quiet, my neighbor came out and sat on his patio to watch me run the new splitter, he was about 20 feet away, and said it is nice and quiet.
My son decided he wanted to help split wood, I got my 3 ton electric homelite splitter out and powered it with my Subaru/Robin Homelite generator. The generator needed to be run, and my gas is free anyway. Comparing the Predator engine to the S/R for noise, the S/R is just a hair quieter, but neither is really that loud. My B&S lawnmowers are louder.
I could actually run the predator engine on the lowest setting and still split any wood I have. I have lots of maple from a big old tree that fell in a thunderstorm, way bigger than the "16 size limit in the paperwork, nothing has stopped the splitter yet. I prefer to run the engine at the middle of the throttle setting.
I still have a few more cords cut and waiting to be split, this baby is going to get a real workout!