ORIGINAL: Chris H
From what I've read/understood AE is using CHS as its basis of the OOB, but I might be wrong. CHS itself has lots of different ships, one of my favourite being the 40kt Abdiel class ML. Which my the way in 1965 could still do well over 35kts and if my memory serves me well, with one of its boilers removed.
AE is based on stock, with new research. Some of the CHS guys are on the AE team but that's all.
The Abdiels are in, three of them if memory serves.
Speaking from the perspective of the Naval OOB, there are many more things that could be done if we only had another 10 years or so. So much research and so much work, and issues with game balance and playability. Many of the new ship classes put in are not yet used (like YP) but are there for the modder. Have fun, y'all.
As an aside, I can tell you that we have discovered some interesting things, even some errors in commenly used web OOB sites.