Its true that there are guys that complain about negative side effects from soy, however usually when this happens there are significant mitigating factors involved. Oftentimes the guy either took too much soy within a short period of time or was taking large doses of soy for an extended period of time. Im firmly of the belief that if one uses moderate doses of soy then there should be no problems.
If you can find any threads where guys experienced negative side effects from soy then please forward them to me so that I can analyze these cases. Im sure there are a decent amount of guys who got negative side effects from soy, but I suspect that the majority of those cases involved significant mitigating factors like the ones I mentioned above.