This episode is just plain good writing (finally). The project and its devoted scientists is just the right amount of intriguing and enough so that it's not too much boring science stuff. Basically, the premise is the project - so the writers set it up but then only use it minimally throughout the show. It's a good device.
Roland is a sweetheart and you really feel for him and his struggle, particularly when he doesn't want to hurt Tracey. The actor was great! And the flashes of dreams used by his twin brother to control him were surprising and scary when they flashed suddenly onto the screen.
I loved when Mulder was helping Roland pick out his shirt. And also, when Mulder first thinks that it was Roland's handwriting on the board - his facial expression when it turns out his first hunch is wrong was funny. He's not used to being told he's wrong. Haha. And lastly, that squelching noise when the scientist gets eaten up by the fan - that's a great sound effect. Appropriately yucky!