I am an Electrocompaniet dealer and although I love this CD player I will state that there are a hand full of great CD players with the Capitol being one of them.
Our experience in numerous shootouts that we have done is that there is no one best player to anyone's ear. We have had up to twelve manufactures and Audiophiles in here during listening tests and the opinions have varied widely on CD player preference. As it would with almost any component. The fact is that we all do not have the same taste. I will also state that the Audio Aero and the EMC sound much more similar than say the Mephisto 2 or Accuphase.
But remember other things will contribute to the sound of your component such as a powercord and interconnects. So the question then becomes which is the better value and can I improve one more than the other for the same amount of expenditure. Unless the prices have changed the EMC retails for $5500 the Capitol for $8800.
You can run the Capitol direct which some people highly advocate some rather still use a preamp. If you like it direct the Capitol and the EMC will run about the same in investment. If you want to use a preamp the EMC is then substantially less expensive.
If price is not an object and if you hear them both and find that you could live with either one. Then look at the built quality. Look at the opportunity for upgrading the player. The EMC 1 came out at $4000, then there was a $1000 24/192 upgrade, and then a recent $800
upgrade available on all their players. They could have changed models and had you sell your old player and purchase a new one but choose to make it as inexpensive as possible for the consumer to continually improve to the new generation. Not being a Capitol dealer I have no idea about their upgrade path or costs.
My personal experience is that once you get to the better CD players the differences are very subtle.
Good luck you will love either one.