Old NAD v New Marantz

Hi all. Opinions wanted. I've had a NAD T747 for years. When I bought it, it was used for stereo, as well as HT.  I now have a pretty good 2 channel system (Anthem, Maggies, etc.) and want to upgrade to an Atmos capable HT system. So the question: would I lose much in terms of sound quality with a high (ish) end Marantz (maybe a 7011) or Denon? 

At the moment the HT speakers are small Athena (remember them?) which would also be upgraded in the future.

Thanks in advance.
I do not know how marantz does with HT, but i can testify about the marantz  quality.  I have had a stereo integrated marantz 8400 (w/ toroidal power tranformer) ON for 7 years 24/7, and it sounds really good.  Not a crack, as smooth as on day one.  Heavy construction, built with hi-quality components inside and out. And it sounds good with my totem hawk.  Unless you find better sounding for the $, know that marantz = seriously solid gear.
I just now saw the notification for this. Thanks for the reply. I actually ended up with a Denon 4300. So far, so good.