With Wave 5 and Rebel Aces in play for many lucky individuals (such as myself) it's become apparent that Decimators and to a lesser extent Outriders are going to shake up the meta in a big way.
Large ships are already a staple on the current tournament scene and their effectiveness is already well established. Fortress Falcon may quite possibly have won the National, and Fat Han/ Alien Loves Predator is a mainstay, nay, cliche, of any tournament at the moment.
The reason why Large Ships are so effective is the general focus in the game on sustained damage over time due to the long-standing swarm meta. Large Ships attempt to take advantage of this by drawing out the game sufficiently to the point where the opponent has insufficient firepower to take down a guaranteed 2-evade a turn turreted ship with Gunner. The Decimator is the Imperial version of this list, but with added threat of guaranteed stress or guaranteed crits, with more HP to boot.
What I've found effective against Large Ships however is the oft-neglected Burst Damage aspect of the game; Ordnance, which has recently been buffed with the release of RA. Will Ordnance finally come into its own?