Biggest impact: moving from integrated to separates

Two interfaces that affect sound the most are a) speaker to room and 2) amplifier to speaker. You don’t say what your speakers are, whether you are happy with them, or what type of sound you’re looking for. Low power SET + hi efficiency speakers is a very different sound than say a tube pre and solid state amp. If it’s the latter you’re looking for, consider a Don Sachs pre ($1,600?) and the new Adcom GFA 555SE at $1,300. Or if you're just looking for more detail and power than the Chronus, check out other integrateds like the Bryston BP135 or Musical Fidelity M6i. Another possibility is the Line Magnetic integrateds, or the LSA Statement(s), etc.

@keithtexas thanks, I like my speakers (ZU Soul MK2) which are 99db efficient.

Why the assumption that separates under $3K will significantly outperform the Cronus? Bryston and Musical Fidelity would be a lateral move at best. 

One of the many myths of audio is that you need separate chassis for ultimate performance. I've heard integrateds that go toe to toe with $30K monoblocks, while doing it with a lower noise floor.

I tend to agree with @helomech.  As a CMII owner, I have inevitably wondered what it would be like to replace it with an RP-5 and Stereo 100, but until I get a chance to hear that combo, I’ve concluded that the difference would in all likelihood be quite small.