Stick with what you have if it sounds good to you, but I do feel the need to point out two things: There have been significant improvements in room correction DSP algorithms particularly in the last decade. You don't need to ditch your amp to add these, there are DSP boxes you can put in the preamp stage. These will improve sound quality considerably. Audyssey, Dirac, and Anthem ARC are common names; there are others.
And there are a huge abundance of speakers in the mid range $200-$600 that are absolutely fantastic; it's a pretty wide market segment. There's plenty of old options too, but... it's not hard to find a new set of speakers capable of great sound at a decent price these days. I don't know what exactly Speakerbits was implying, but it's not true now.