Sounds more like you've made a decision and you're looking for someone here to agree with you so you feel more confident in your choice.
Sound-wise: I couldn't disagree more but for personal reasons. I had the option of purchasing a used F90 M5 a few days ago (and driving it immediately today) vs. a completely individualised M3 that I'm now waiting 4-6 months for (I'm a very impatient person too), and I opted for the G80 with little hesitation. I don't like V8's - I like screaming 6 cylinder engines. I didn't have much interest in the sound of the G80 until I heard a modified one:
I much prefer the howl and wailing of a turbo I6 than a turbo V8. I have yet to hear a BMW derived F/I V8 that sounds amazing. Looks are completely subjective too.. I personally would rather an 8 series over a 4 series, but I need 4 doors; so my choices were: new tailored to my desired G80 M3, used F90 M5, or M850i Gran Coupe - I chose the G80. Tough to beat a 6MT at the end of the day.
If you really don't like the sound of BMW's twin turbo 6 and don't like the styling of the M4.. then you already have your answer as to what to do.