In order of preference, because I test drove all of them.
C43 AMG, keeping in mind it'd be the 2019 facelifted model - was everything I wanted, but was also 80k for a G70-comparable spec. Couldn't justify that money on a car. Amazing to drive, crazy sound, extremely comfortable. Very possibly a future buy once finances allow.
G70 Sport, which I got. By a pretty wide margin the cheapest of all but the
Infiniti on a lease thanks to a high residual, especially with the maintenance factored in. Actually within $5/week of a Golf R.
Audi S4, great car but lease payments are absolutely nuts. Not as engaging as the G70, I thought. Dealer experience was very meh.
BMW 340i, very dated and feels slower than it is. As a former BMW owner, this is a very disappointing car.
ATS V6, well it feels very much like a GM product and not as a premium vehicle. Didn't like the dynamics, dealer experience was very bad, in typical GM fashion.
Q50 Red Sport is last. Steering is horsecrap, doesn't nearly feel like a 400hp car, and it's got the interior of a 2014 Nissan, which is not a compliment. I had a supplier rebate and would have had a better price than the G70 but I didn't see myself enjoying it.