I have owned a few decent devices, Yamaha Z11 for a couple of years then a Denon 4810 (Audyssey XT) for also a couple of years then now a Marantz AV-8801(Audyssey XT32) for around 7-8 months. before that had 3 Onkyos.
I like the 8801 the most, love the XLR connection as i am using it for all my speakers, all connected to my 3 Emotiva's 2 XPA-5's and an XPA-3.
The XT32 in the Marantz is far superior to the previous Denon i had, and i think i will keep the unit till at least another 2 years. i did notice a significant increase in detail clarity compared to the Denon.
Surrounds were more live if i could say so and LFE is more controlled and focused rather than boomy or exaggerated. i can even notice my surround backs for the first time without raising their level! i am not using dynamic eq or audyssey volume.
Blackdevil since you have a full Seaton setup that uses XLR connections i would suggest you use them that way. at least for me when i went all RCA to XLR i did notice a difference and also there was no more humming.
If you can wait for a couple of months then you can at least see/test the new Marantz AV-8802. which i think will be amazing. it will also have Atmos and Auro 3D.
The AV8801 is definitely an awesome processor. Reason I didn't get it was because my DHC-80.3 was brand new at the time, I heard there wasn't enough of a difference to get it, and that it would have been more of a "sideways" move. My DHC-80.3 also has XT32 like the AV8801. I'm guessing the AV8802 has the new revised version of XT32 that audioguy was talking about that the AV7702 has.