That's a nice opinion, but I don't see any supporting evidence to back that up. When you have some, let us know, in the meantime.
Define R5 anechoic chamber testing.
View: https://www.youtube.com/watch?v=dVdkIi9iUVM
And the Define R6 is, seemingly, better.
https://www.gamersnexus.net/hwreviews/3177-fractal-define-r6-case-review-mid-tower
If you don't need drive cages in the business side of the case, then the Define S2 might be an even better choice because without the drive cages and shroud sitting there directly behind the intake fans, the GPU temperatures are far better than with the Define R6, and the only realistic difference between the two cases IS the drive bays and shroud on the left side of the motherboard tray. A custom or self modified front panel to go from stock to full mod mesh improves things even further, but obviously at the cost of some increase in noise levels, which again are nullified if you populate all the drive bays with the very quiet Noctua fans.