Some DDR3 can handle up to ~2.0V, others will begin to degrade as low as 1.7V. I've never personally heard of any DDR3 failing due to "too much voltage" when run at 1.65V or less.
The "link" you gave to your memory doesn't work [it's dependent on local conditions], so I can't check specifically which RAM you have, however, provided you have heatsinks on the memory (or at least heat spreaders), then up to 1.65V should never be a problem (All chips will suffer from a point of diminishing returns on voltage though, so there is a point at which there is no advantage to more voltage). A simple but effective test, while running a memory intensive stress test place a finger on the memory heatsink. If it's warm to the touch, everything is fine, if things are uncomfortably hot to the touch, then you're probably venturing into territory that won't return any benefits so back off on the voltage.
Very often, the same ICs of the same or similar binning used on a kit sold as a "basic" 1.5V kit, are used in a "high performance" kit sold with a higher XMP profile and 1.65V "defaults" instead. DDR3 has been around for so long now, that most of the manufacture processes are refined to a point that most ICs coming off the line are way beyond the minimum grade required to meet DDR3 spec. The result of this, is that there simply aren't many "bad bins" available to fill demand for "regular" ole 1333 speed DDR3, so they just use good stuff. From the perspective of the RAM brand, it's important to have a product offering at a wide variety of speeds/timings/voltages simply for market saturation reasons, even if they all have the same ICs.
Edited by mdocod - 1/21/14 at 7:20pm