Comparing an 290AJ to a 370EC isn't really an apples to apples comparison.
The EC is designed for bigger water and better handling than the 290AJ. The benefits are better sea keeping in heavier seas, much better handling around docks and in open water. The EC has a keel which makes them track like they are on rails........they handle s lot like much bigger than 37ft boats. These boats were designed to compete with Tiara and Cabo in the mid sized fishing market, but give the buyer typical Sea Ray ammenities, fit and finish, so they were built with big boat features but did not sacrifice on creature comforts. The AJ is a much smaller boat and acts like it. The 370EC is one of the best boats Sea Ray's designers have given us.
Separate the cosmetics from the bones. You can replace fabrics, canvas and vinyl to make an older boat fresh if it needs freshening or upgrading, but you can't add overall design features to a newer boat that doesn't handle well, isn't wide enough, throws spray in your face, etc.
We have a couple of EC's in our area that the owners have completely upgraded with teak/holly cabin soles, leather interiors, ostrich hide wall covering, one has a teak transom, and they are real show pieces. This boat is one worth investing $$ because there is a steady demand for them, especially diesel models with hardtops.