You already have a first rate regulator, what don't you like? Or, what features do you think are available in the Oceanic that are lacking in the Legend LX. You already have cold water covered with the Supreme.
Now the EOS has the new Dry Valve Technology (DVT) but I'm not convinced this is anything more than another marketing gimmick. I'll hang back a while and see how it comes out. At first blush, I'm not a fan of more things in the air path. OTOH, it may turn out to be the best thing since the original Aqualung. Who knows?
There's no way in the world a piece of plastic molded to the shape of a regulator is worth anything like $600. For my son-in-law, I bought the Dive Rite Hurricane ($399 most places) and it is a great regulator from a company that publishes their service manual on the web and sells parts to end users. Not that I think doing regulator work will be on my career path but it is a nice gesture.
If you really want to change regulators (not that I think there will be much of an upgrade), consider the Hurricane. It is still overpriced (in my view) but it's a couple of hundred bucks less overpriced than most.
On the downside, it is DIN only. A consideration, not a show stopper.
Richard