I wanted to use these speaker stands in an audio art installation where the visual look is also important. The stand with the round base definitly looks nice, and it is fairly stable. However, compared to it's tripod brother the stands is quite a bit less stable than that one. I also believe the weight in the description is not the weight of the base alone, but of the whole speaker. It starts to wobble a lot faster than its tripod brother, especially if you are using non center loaded speakers. The round base also makes it much more difficult to use the stand in places where the floors aren't perfectly flat.
For light center loaded speakers you want to put on a visually pleasing stand, this stand is ideal. But for not center loaded, or slightly heavier speakers, look towards the tripod brother or get a stand with a heavier base.