I was out of town when the Wave 4 announcement hit so I haven't had a chance to talk about it yet. While the Wave 3 flotillas were fun and will no doubt have a huge impact on game play, they aren't what you would call eye catching models.
Wave 4 does not have that problem. The Liberty and Interdictor are two of the most anticipated models in Armada. Both look great and I can't wait to get my hands on them. Here's hoping for a GenCon release!
I'm also really pleased they went with the Interdictor from the Rebels show. I am a huge fan of the show and really pleased to see the ships and characters making into FFGs games. While I appreciate the old EU designs, I am happy to see FFG transitioning to using primarily ships and characters from the new canon.
If you look at Wave 3 and 4 for Armada as well as the recently announced Wave 9 for X-Wing all of the designs have appeared on screen as a part of the new canon. I think this is significant and should tell us what to expect in the future. Both Disney and FFG have an interest in the games containing designs that are visible in the new canon.
From a game play standpoint, the Liberty brings some interesting new possibilities to the Rebel side. In many ways it is like a large Nebulon, with a strong front arc and 2x Brace tokens. That double brace will be a big deal and make it fairly survivable in head on confrontations.
The Interdictor seems to follow on with some of the support abilities of Wave 3. The couple of upgrades spoiled will have a huge impact on the flow of the game and it will be interesting to see how effective that they are in practice.