Hi Dave. My first drive in a Roadster was in a Series 1, and I thought then 'ooh, this is nice, I could take to this...'.
Then I drove a 3.7 a week or so later and thought 'ooooh, this is even better!'.
Apart from the bonkers dash (you're right, the Series 1 has the best, and most logical dash arrangement), I was impressed by the way the 3.7 felt on the road. Maybe it was the power steering, maybe it was the weight of the car, maybe because it was a much later car (the Series 1 I drove was a 2004, the 3.7 a 2014 model) but it certainly felt more settled and smoother to me. It did seem to suffer a wee bit from rev hang, but I didn't think it was too much to worry about, so maybe it had been sorted on this particular car.