To be clear indeed I was talking about two S500 stereo amplifiers and not the monoblocks. It is also not so much a seller trying to push these on me, but me trying to buy something second hand. The seller itself cannot even part with them yet as he himself is also sourcing for some new parts first, so there luckily is no haste involved on that front! Sadly the person lives a country away and Red Dragon is not really present here in Europe it seems so demoing is not an option (Which I understand is a risk).
Tim, thanks for your detailed reply! Regarding my room. It is a living room with an open kitchen. 7.5x5.5m with one side of the 7.5M being all windowed. Floors are tiles so there are a lot of hard surfaces. As this is the living room, conditioning the room is out of the question, so I am thinking of trying to solve this with room correction such as Diriac (I am afraid that these words in combination with Class-D will only anger some people even more :-) ) In my circle of friends I only have one person who is a music fanatic and indeed I am planning to spend some time listening to his setup. I also have an appointment with our local hifi shop soon.
The AVR was bought at some point as I was connecting a lot of things to my TV but in reality I just have (and only want) 2.0 or 2.1 depending whether my next set of speakers will be monitors or not. I am a big movie buff but I do not care for surround sound at all and rarely watch action-y movies where this plays a big role. Between audio/video lately we've gone to 65/35 split audio/video I would say. Music wise I am still refining my tastes but I listen to a lot of (prog-) rock and some jazz. Classical would really be every once in a blue moon and then there's a plethora of other genres we listen to every once in a while (from salsa to hiphop).
Regarding to what exactly I want to improve: I cannot call myself an audiophile yet at all, but if I would describe what I find lacking it's that the sound does not really seem to envelop you. I can put my set louder but it does not have *presence* in my room I guess, it will just be more sound. I have difficulty expressing whether I find my set sounding cold or warm, alive or not as I think I lack the experience to compare it with anything else.