When you say "make a difference", what do you find lacking in your current setup? The NR3030 was top tier so I would not expect a significant change in sound. What probably has improved the most is auto speaker calibration. Audyssey and Dirac have improved since AccuEQ, but are you using the AccuEQ room calibration?
The Onkyo can upscale to 4K, so are there any video features lacking? Do you need HDR and Dolby Vision support?
Do you foresee adding more subwoofers? The Cinema 30 supports 4 subwoofers and adding Dirac DLBC would help bass management.
Unless there are specific features lacking it might be hard to justify the expense but others may chime in with differing opinions.