Should I buy Anthem 1120 for a 11 speaker system or Sony 5000 ES

Have you listened to both units side-by-side?  Even without ARC enabled you are going to get much better sound out of the Anthem 720 compared to the Sony,  Thrown in ARC and the gap is even bigger.  Anthem will give you much more headroom to work with as well.  The power supply used by Anthem is much more robust. 

I have not yet. I have an appointment tomorrow to audition everything. It will be interesting to compare the 720 to the Sony 5000. Have you done the comparison?

Yes.  I felt the Anthem produced a much cleaner sound, more power, and with ARC you cannot go wrong.  

Anthem dealer here, we just installed in the last six months a few MRX 720 and the 1120, the Anthem ARC is just amazing.

We had a client with a really weird room open on one side with french doors on one end, and the seating was at one corner,

We listended to the system without the Anthem Room correction and then did the correction and boom with ARC tiny details emerged, the overall presenation was smoother and the dialog was clearer.

ARC is very impressive and the new ARC Genesis promises even further improvements.

Really hard to beat at the price point.

We have also sold and installed many other receivers including Onkyo, Marantz, Denonns and Yamahas and again never heard anything for the price better the Anthem.

Dave and Troy
Audio Doctor NJ Anthem dealers

@audiotroy Hi Audiotroy, Have you heard the Sony ES? I will probably buy the Sony 5000ES that my dealer recommends. He and the other co-owner worked with Sony to design the 3100ES and  5000ES.
They have sold Anthem forever, they have been in business for thirty years. I heard the Anthem 720 there before I heard the Sony. I thought the Anthem was really excellent and I thought about buying. After working with one of the co-owners he convinced me that the Sony is better and then later I talked with the other co-owner and he said the same. To be honest I was surprised that they even sold Sony as my attitude about Sony was that it was not considered hi-end at all. This store only sells very high-end. I finally got to listen to the 3100 yesterday with Paradigm 75F and 45C. I thought it was amazing, two channel and Atmos. I haven't bought yet so I would like your opinion of 5000ES as that is the one I would buy. 
Also I would like your opinion on whether to buy the 55C or the 45C to go with the 75F that I have decided on. The co-owner who I have been working with told me that all I need is the 45C as that is the center speaker that matches with the 75F. Money is not an issue, I just want the best match. 
The other co-owner told me to just go with a 5.1 system and forget about Atmos. He said for the money that it would take to make a good 5.1.4 system its just not worth it as I would mostly be watching non Atmos sources. I would be using my home theater for a lot of CD and streaming music, we watch a lot of news shows and also HBO and Showtime that we stream. We also stream a lot of shows from Amazon and Netflix. I would be buying zero 4K disks. Also I am guessing that the shows that are Atmos enabled, only action type shows would really take advantage of it. We mostly watch drama and comedy. Thanks for any opinions you can offer