Experienced a Yamaha FZR1000 at 150+ mph on the A414 towards Harlow once upon a time. Nice straight-ish road, and sure it was fast, but involved, sorry no. Was more a case of hanging on to a big lump and it left me a bit cold.
The 414 from Chelmsford across to Ongar and then on to the M11 is a great road, but the deer are a bit partial to appearing from nowhere, especially at the times of day that are most fun for driving.
Re the GC, I drove one before I bought mine because I wanted to test the auto box. Kept the roof up (it was raining) but was a bit surprised by the wind noise. Much worse than my old Merc cab had been. And the boot was just laughably shite. Look good with the roof down, good for posing (but seriously... posing at all of our ages??) but not practical enough. A dream garage of 10+ cars might have one but I doubt it would come out much. My other one-day cars would see far more use.