Is it unfair to compare it with the Cayman R? Yes and No.
Yes because the two cars aren't direct rivals to each other, not in a month of Sundays would anyone cross shop these two cars, that and the fact that one is a proper performance coupe that has been taken a step closer to a trackday tool. But here is where the No comes into play, the very fact that the 1M is being compared continuously with this car shows that on sheer ability and entertainment it isn't that far off, yes it's controls don't feel quite as percise, yes it's not quite as polished a performer but it's bloody close and for a fraction of the price. On sheer looks alone I reckon BMW have hit the nail on the head with what they want it's perception to be, i.e. a mean little fu@ker that you don't want to mess with. It's engine/exhaust note doesn't live up to the way it looks, though an aftermarket exhaust will probably help here but it's a shame it's an extra expense that really needs to be allowed for.
The only niggle about the 1M in my opinion and was part of Steve's opening comments was that it's scary to drive quick and that you need to know what you are doing or in other words it will take no prisoners if you over step the mark. Because of this fact there will be many who will love to own this car though won't necessarily have the ability to drive it properly. Bodyshops the world over with do a roaring trade because of this.