Very stable, no significant bounce that I've noticed. We've got high ceilings, so I bought a tallish (3.8m) version so that we can either extend it up into the loft for safer access, or just have it reach high enough for a quick nip up there. The ladder is rated to 150kg, and as we don't have anything up there which weighs anywhere near my own body weight, I can't see us getting near to that load!!
(This was the product we bought -
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we had this we had a very flimsy A frame step ladder that flipped out to a single length instead. Had a very near disaster when bringing down an old metal cold water tank from the loft - foolishly I let my wife lower it through the hatch, and I took it over my head - very nearly went crashing backwards disastrously, but just about managed to get it down without doing any damage.
Matt
Matt