I don't have these speakers nor have I mounted them on different stands... but in response to choirboss:
If your speakers are falling over realtively easy, wouldn't that be an issue with the base? When things fall over, that be because the center of gravity of the object extends over the base of the object... not necessarily because it is too heavy.
bigger base = more stable (in terms of falling over)
the base has a footprint about a square foot wide, with copper spikes supporting underneath for carpet use... its actually very topheavy though, i considered using concrete cinderblocks to fit overtop of the base to balance them out more, which would work... itd look fairly out of place though, and dont have any onhand anyhow... otherwise though, the speaker stands are firmly in place, (aside from when you knock them over)... but, thats also why the stand weight capacity would matter, because my speakers are just under that weight, and theyre just that close to being completely unstable (the speakers themselves dont extend past the stand base though)... ...at frys though, they were the most capable stands i could find really...
i suppose if the base otherwise was about 3-4 square feet wide or so, it wouldnt fall over like youre saying (cuz they might then support a speaker weight upwards of ~50+ pounds even)... but that wouldnt fit anywhere then really
i guess if anything i could try changing the alignment of the speakers themselves, from verticle, to horizontal... and that would broaden and lower their center of gravity a tad