For whatever it's worth, this service was unable to find any location for my phone that only connects over 2g, but had no problem tracking my 4g phone with startling accuracy.
This is true, but I suspect something else might be going on. LocationSmart said it couldn't find the location of my phone at all, but even if I'm visible to only one tower it should at least be able to narrow it down to the location of that tower.
