the 60's come with spikes and rubber feet, and you can interchange them to whatever conditions you have. or, you can just plop them straight on the floor, its up to you. i use the spikes and i have a medium thickness carpet.
they can be a little "tippy" with the spikes, but not overly so. if you give them a real solid nudge, they will rock a little, but i think they would still do it with the rubber feet, or directly on the floor. i think thats one of those deals you will just have to decide once you get them in your house.
good luck..
bigjohn
