I trust http://lygte-info.dk. He tests and reviews an astounding number of cells, and has an amazing cell comparison tool, http://lygte-info.dk/info/batteryIndex.html. I've used that tool to compare cell capacities at various discharge currents.
To test discharge yourself, read his page, "how is the test done." And, please know what you're doing if you decide to approach the manufacturer specified max discharge or max charge current.