There is something pleasing about watching a mile-long spacecathedral circling in broadside combat with a mile-long, meat-covered spacecathedral dedicated to ruinous powers. Something to do with pretty space backgrounds, nice giant spacecathedrals, colourful zapbeams, and the very idea of heavily-armed shards of meat, bone, and teeth. I'm less sure about the ship with a big silly red demon heads on top, though. Maybe that's what Red Nose Day will look like in 38 thousands years.
Chaos ships are fast and can fight at long ranges, which is handy because compared to the Imperial Navy they're squishier (sometimes literally, if you follow the right Chaos god). The game has a fine-looking lineup. Chaos ships are over-the-top evil, Ork vessels are over-the-top scrappy, the Imperial Navy are mega-ornate, and the Eldar are... hm, I suppose Eldar will be the next force getting a showing-off.
Battlefleet Gothic: Armada is due to launch in March. Adam played an early version a good year ago, and quite liked what he saw then. Do have a read of that. He can tell you about the game, whereas I'm clearly just distracted by teeth on a murdership. (But what does it eat! Does it have a bum too?)