gdstaples wrote:
Do I need to worry about this or should everything be ok? Why would Canon add a PC Sync if it couldn't attach to most common strobe equipment? There was no warning in the instruction manual about voltage issues with studio lighting equipment.
Duncan
The Camera manual do say about the camera's inability to handle Sync voltage beyond 6Volt, but it surely does not mention what will be consequence if you try to trigger a Strobe having 200 Volt Sync voltage!
Canon heavily promote and suggest Canon's own dedicated flashes like 550 or 420s They are very capable flashes with matching Canon price tags 
A similar feature flash from Sigma will cost half the price of Canon. So why should Canon be interested to provide you all the necessary interfaces with their camera? They do not even want any third party to develop cheaper compatible products for their camera's. Remember, Canon does not provide any interface protocol of their flash or EOS Lenses with their Camera body. Third party manufacturer like Sigma, Metz etc. just have to reverse engineer Canon flashes and Lenses to figure out how they talk with the body. So many times, third party products gave compatibility problems with various Canon bodies.
I will advice to measure your flash sync voltage. A digital multimeter set in DC voltage range 20 can measure it. Turn on your strobe and wait till its ready lamp glows. Now touch the two metal contacts of the pc cord end with two probes of your meter. The reading you get is your strobe sync voltage. PLEASE REMEMBER to set your strobe at lowest power and turn it away from your eyes, cause while measuring if the probes touch each other, the strobe will get triggered. A full blast of light very near to eyes can cause temporary or permanent blindness.
I am very happy with my set up as I do not have any need for ETTL. Most of the studio photographers also perhaps care less about ETTL. For studio work, the main requirement is variable power strobes. No auto metering as metering is almost always done by ambient flash meter, or by visual trial and error and bracketing.