Any experience with Eastwood's Optiflow roll-on primer??

I'm trying to do some research on prepping/priming my car before I start to paint, and I came across this video on the Tube by Eastwood. It's a roll-on epoxy primer called Optiflow. Eastwood has a decent reputation, so I'm wondering if they would put out a shoddy product. Seems convenient, but how on earth would you be able to achieve a smooth finish without roller lines?

Has anyone used this stuff?