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The Canon TC-80N3 is small and compact, and the small battery it uses lasts for a very long time. It is easily light enough to let it hang from the connector off the camera with no thought of a problem. I am very happy with the one I have, and I first used it with my EOS-3 quite a few years ago.
The Canon connector does lock in to the camera very well, and yet releases perfectly when you pull on it. I have always been worried about third party connectors going into an expensive cameras, and the only third party one I worked with did not give me much confidence. And the reference to my post above still applies. Some third party connectors may not fit properly if you want to use them with L plates. I don't know how big a problem the fit issue with L plates is, but it is just another thing to be aware of and consider.