This was the choice I faced as well.
BMW S1000RR "M"
I have a BMW R1200S and have been a fan of the marque for both cars and bikes for come years now. At first, for me, the 2020 S1000RR M edition was a simple choice. I test rode a 2015, 2017, and 2018 S1000RR. The 2017 was near perfect but felt a bit small. Later research has suggested that this is the pinnacle version of the bike. Abruptly, the 2020 S1000RR M I was ready to buy received a "no-sell" advisory as soon as it arrived in the shop. The answers to "why" were a bit cryptic but I was pointed in the direction of the link below for clues.
Draw your own conclusions from the 740-odd posts.
For me... the significant flat spot in the ECU (fixable for CDN$1000 on top of the price of a new bike, possibly/probably voiding the warranty... although there are work-arounds for that blah blah blah) was a bitter pill for a new bike. Then, add cracked carbon fiber wheels and a long list of leaking bits and substandard parts ... pretty much closed the book on that bike for me. Perhaps the 2021 is an improvement, albeit even more costly.
Ducati V4
Test rode a 2018 and 2019 V4 and V4S. Sat on the 2020 V4. Bought it. Happy.
If I had been more confident of the long-term health of the S1000RR I would have bought it, despite the need to address the ECU mapping. The dealership even offered to switch out the carbon wheels for forged wheels... and then retracted the offer because BMW said it would void the warranty because the "as sold" registry of parts and equipment would have been altered. Again, my alternative was to buy a second set of wheels as an aftermarket purchase. Absurd requirement for a new bike.
One man's experience and opinion. Best of luck.