UEF Research Converter: Research Conversion Facility: This structure provides the option to generate Research directly from accumulated mass. It is highly inefficient, but produces an instant boost to research.
Despite the ineffeciency, the Research Converter provides the ability to gain large numbers of research points in an instant. To do this, you must first construct Energy Generators, and then Mass Converters. Then, you can convert the Energy to Mass, followed by the Mass to Research. While this tactic is simply not plausable on smaller maps, on larger maps with a rush timer, this allows you to research multiple entire trees in a rather compressed time frame. In addition, research converters have one additional benefit over research stations. Once you have researched everything - which can be done within 10 minutes, if you're serious about it - you can reclaim the Research Converters (as well as perhaps some of the Energy Generators) and easily recover 20% of the mass spent to build it all. Combine this with the cost difference (Research Converters cost around 50% less than Research Stations) and it becomes viable to have an early research rush, then sell it all off once you're done with it. By contrast, Research Stations cost almost twice as much, and with 8 of them, will still take over an hour to give you enough reseach points for all the research the UEF has, meaning you'd have to wait that entire time to reclaim them, and be at a disadvantage to your enemy technologically in the mean time.
That said, the amount of energy needed to use them effectively is simply excessive, so if you're not planning to do an early rush with them, you're better off not using them at all.