MotorTrend posted a review on the 2018 Mercedes AMG GT Roadster and the GT C Roadster as well. It is a lengthy review but MotorTrend does supply some good information when they do reviews.
Even if you don’t turn back, you’ll be doing some moving around in the seats. The seat bottoms are very firm and quickly become uncomfortable, and there aren’t a lot of options for shifting your weight around, as the bolsters are very large for track driving. They’re great sport seats, no question, but for a touring car, they’re too aggressive, and most drivers won’t spend much time at the track. An optional comfort seat would be wise.
They did like it however, but give it a quick look, there is also a huge gallery to go through as well.
Definitely wouldn't be using this as a touring car at all. It'll be for the spurts around the place, maybe an hour drive to an hour and a half at most. From here to cruise through the north a bit, take some photos, and come back home.
I'd like to think my butt is forged from the finest steel and it'll break in the seat before the seat breaks it in. What you get for a slightly uncomfortable ride more than makes up for it; that 20 hp and 21 lb-ft increase in the Roadster and 47 hp and 23 lb-ft in the GT C. Base GT Roadster's output of 476 hp and 464 lb-ft is nothing to sniff at either.
That's the thing a lot of people tend to forget though, they see the AMG GT R numbers and look at the base one and think oh... well it's not as fast. But the base model is still plenty fast and more than the regular can handle which is amazing.