Thats what I thought about the Cayman I had out on track. Interior is no doubt put better together with better materials, but it felt so boring in the cabin and quite cramped. On track the car was very good, better handling than the 350z I had at the time, but somehow lost a bit of the fun the Zed had. The 370z is somewhere in between the two in handling terms for me.
As for BMW vs Cayman, if it was a weekend toy, I'd take the Cayman hands down, but if I could only have one car for all it would be the BMW.