The thinner the lines in your render the more you would want to go to fine art. Rigging in a ship for example would be a good one for fine art. Just a ship with a sunset and no thin lines wouldn't matter so much. However, the larger you want to render, the more likley you would want fine art. its a detail thing. If the fine detail just doesn't matter cuz its a 640x480 render for a 12 inch laptop screen then who cares. If someone is going to be looking at your work up close and personal, like a poster or portfolio, then fine art starts to make senses.