You make a crucial point, which is that cars are a highly subjective purchase. If it was all about functional utility, then you could buy the best car for your budget using a spreadsheet. But emotional utility is at least as important, and is something that differs for every person. Hence the wide range of differing positions from reviewers - even assuming they are trying to be objective.Very keen to hear a 'real person' reviewing this. Even the paid-for/influenced reviews have not really loved it universally. Having seen it in person, my opinion has unfortunately only gotten worse on the styling, but this doesn't matter if it is an absolute blast to drive. I'd be interested to know how close your spec came to an M3/4 which (according to throttle house anyway - they are usually aligned to my views) is in another league of fun and engagement (which I'd have hoped would be in the M2's favour). That being said, reviews these days can't really be trusted and we all have preferences. When buying a car like this, it is often more head than heart and more the lovable faults/characteristics that get you (which is why Audis are always excellent yet always so boring and never really sought after used).
I doubt you will be disappointed once you're behind the wheel and even then I doubt you will find it difficult to move on if you are.
On the manual front, it has become very tiring hearing people think you aren't a purist if you don't buy a manual, while happily driving heavily damped manuals with soft clutches and (my pet hate) auto rev-match. I think going auto was the right choice and you shouldn't feel 'bad' about it. The manual hype (I am sorry to say) is dying. Anyway the "but I wish it was manual" crew just don't put their money where their mouths are when it comes to buying new or used cars. With modern powertrains, DCT and auto boxes provide not just the 'faster' experience on a track but can actually be better mated/more engaging even in the real world. Modern manual boxes are not what they used to be (or what people imagine they will be like) and this also factors into decisions of those actually in a position to buy them... Manuals IMHO are best with high revving NA motors (GT3/4, E9x etc). These are a fraction of a fraction of cars on the market today.
I will say I absolutely loved the GT4 driving experience EXCEPT the bloody auto rev match which couldn't be turned off in sport mode for some bizarre reason (at least the sales person couldn't do it). If you are not in love with your M2 then perhaps go and drive one of those.
I also agree with your point regarding what the "purist" position. I initially chose manual because a key criteria for me is the driving experience and I thought that a manual gearbox would enhance that. But one thing that did seem universal in the reviews is that the auto is better for extracting the performance potential of the car. And that tipped the scales for me in terms of my definition of driving experience.
In regards to the GT4, funny enough I did across consider it because these are univerally reknowned as being superior drivers cars. Budget was the problem, however. I know I could possibly get used GT4, but I felt that if I was going to spend this kind of money, I wanted a new car. I like my toys new : )
Thanks for your comments, I'll post here about my experience with the M2 soon as I get a change to drive one.