I have a Mantis, as well as a normal sized rotavator. I can no longer use the larger one and will shortly be seeing if I can still manage the Mantis. The Mantis is in fact more thorough in its tilling than a larger machine. I use mine mainly to chop up rotted manure into the soil before planting, after my OH has gone over the ground with the larger machine, and for weeding between rows.
I do find stones a problem as they get caught between the blades and can be difficult to get out (the answer is just to take the tines off and the stone will drop out). It is recomended to use the Mantis by pulling it backwards, but I prefer to use it forwards like a normal rotavator - backwards it is more prone to pick up stones. Our first was a 2 stroke - big mistake and they no longer make them. With the 2 stroke, if you ran out of fuel the engine seized - no lubricant as of course with 2 strokes the oil is in the fuel but ours seized in a second flat. It was replaced be Mantis with a 4 stroke which has been great.
With the larger rotavator we had to rig up a string to keep the throttle open while working (very bad H&S
), as both of us soon found our hands had pneumatic drill operators' white fingers. The Mantis is much gentler on the hands but does still vibrate a lot. It is very easy to lift and carry around, or it will run around under its own power.
The Mantis is far more useful than you would expect for such a small machine.
Here endeth the advert