Either speaker will reach 105 to 107 dBC peaks at your listening distance. That may sound ridiculous to some; I would have considered it ridiculous as well before I listened to ADAs. The fact is however, at my 12 foot listening distance, many songs produce those peaks and they are clean with my ADAs.
That brings us to your Denon. It will not reproduce those peaks faithfully. It will dynamically compress them with its compression circuitry. The next effect will be suppression of your emotion. I had no idea how terrible this effect is until I did a head-to-head comparison of my Onk against an ADA. At lower volumes, I can take my Onk. But for a truly astounding soundstage, the Onk cannot beat the ADA.
Back to speakers. Which one? The M5 or M22? If you go with the M22, you can drive it to those peaks with an ADA-1000. If you go with the M5, you will need the ADA-1250 as a minimum. Setting that aside, does the M5 sound any better than the M22? Unfortunately I have never heard the M22v4 so I cannot say. I can only speculate that the M5 will disperse the mids better and the mids will sound better on it than the M22 because the mid on the M5 is not being asked to carry a lot of bass duty like the M22. I can also speculate that the lower highs sound better on the M5 because the mid is not being asked to play as high as on the M22. Then let's talk bass. Most will tell you if you have a sub, going with M22s is ok. However, I will once again speculate that the improved bass performance of the M5 will give you a fuller sound because the cross-over between speaker and sub is not a cliff but rather a smooth hand-over.
If an ADA sounds like too much money, you have some choices:
1. sit closer
2. forget about enjoying the peaks and all the emotions those offer
3. get more sensitive wall-mount speakers like the M100s.Edit: scratch that last option. At your listening distance, the M100s won't get you all the way to the peaks.
Here is my (long) review of the M5 and M3, both v4.
https://www.axiomaudio.com/reviews/index/list/product/930/
