I hear you guys. It seems precarious, and I was overly cautious/hesitant at first. Trust me, I take extra care positioning the jack feet under the car to ensure it can't suddenly slide off balance and topple. I also figured out where to shim the jack stand based upon its location on my slightly undulating floor to make it perfectly level before hoisting anything. It only takes two minutes to roll it around and lift the car now that I know the varying slopes of the floor, the geometry of the stand, and the optimal distance to position the car from the lifting post. Surprisingly though, you really can pull, beat, and bang on stuff without worry. I suspect that part of that stability is due to the 1200#+ counterbalance the post itself provides.
Cool part is that I'm 6'3", and can walk underneath the car (but not underneath the jack legs or wheels) with no issue. Actually that's the second best part, because the BEST part is that I can move it to any part of the garage with ease, set it up without breaking my back having to assemble anything, store it out of the way when I'm not using it, or just drive over it like a speed bump when parking the car, even though I'm lowered.
They say these can lift Suburbans, but I'm going to go a step further and try to see if it can lift my diesel crew cab. Will let you guys know!