<font color='#000000'>Greetings Borg,
From your budget of $700, you have a good list to start with. I do not have time to dive into a detailed description of each unit now, but I can tell you that the Sony 4ES is a really nice receiver for the money, but I have some reserve about buying it. My detailed article (promised and pending) will tell you about this unit, but real quick.
1) The user interface - Remote Control - is not very user friendly. Many, much needed functions, are not easily accessible when needed via remote.
2) Sony replaced conventional optical connections on the back panel, with "easy access" trap door connections. Although their easy to use, ie you just fit the fiber connection in and the trap door opens, it is not reliable. The trap door is required for friction to hold on the cable. Well, if your like me, and disconnect/connect your cable a few times, you stand the risk of breaking the trap door and there goes that connection.
3) I'm not that impressed with it's DSP capabilities.
My recommendation for now is to hunt down a Sony STR-DA5ES if you can find it. Although it is 6.1 and not 7.1, it is considerably better than the 4ES, and who cares about the extra rear center channel? There is no need for two, mono channel, center rears. One is even debatable, but if you must have it, it's OK.
If you can't find a 5ES, then look more into the Yamaha and the Denon.
If you need more info, let me know.
Happy listening.
Steve</font>