No offense, but I'm surprised by this review and disagree with most of the comparison.
First of all you are trying to compare a smaller 2 door sports car to a larger 4 door Grand Touring vehicle. Second, Infiniti is actually the luxury car branch of Nissan so again Apples to Oranges. However I will say that many did compare the Stinger to other entry level luxury cars and its on par with some of the best.
As for the comparo to Infiniti I personally drove the similar 4 door Q50 Red Sport 400 and had the opposite driving experience. I do agree with you that Infiniti will easily negotiate on price, but that is because they are a dime a dozen. The dealers I went to had over 50 Q50s but only 5 Stingers. Not to mention Infiniti has already sold thousands of that same model for the past few years. So in general you will pay more for rarity, but it's worth every penny when your the only one on the road and everyone is admiring that uniqueness.

However you can get a great deal on the Stinger as I got my GT2 for under invoice.
Next, the Q50 has less torque plus the power curve is much higher in the RPM range so the opposite is true. I had to wait for power to build and it didn't feel strong until 4k+ even in sport mode. The Stinger has such strong torque from 2-4k there not even in the same league, especially for daily city driving. I don't want to have to floor it all the time just to feel the power I'm paying to enjoy.
As for the ride the smaller Infiniti is more nimble, but my GT2 with suspension in Sport mode controls body roll significantly. It feels much more stable, especially coming out of corners & emergency lane changing maneuvers. The same ride over railroad tracks was incredibly smooth in the GT2, but the Q50 felt too taught and was jarring. Not sure if the GTs suspension is that much different than the GT2 but the ride was another reason I got the Stinger over the Q50.
The Q50 brakes do bite more but not in a good way. They are way over boosted and too touchy. I couldn't get used to them ever after a long test drive. The GT2s just felt naturally weighted and strong. Very linear stopping power and was so easy to drive I felt at home within the first mile.
Overall the GT2 felt like a plush, solid luxury sport sedan, when the Q50 felt like a luxury version of the Nissan Altima. The Q50 is no doubt a great car but in the end the Stinger is leaps and bounds above it in every way. That's why they compare the Stinger to Porsche Panameras, Audi A7s, and BMW 640 Grand Coupes, not upgraded Nissans.
This car is truly in a league of its own and I'm so happy i will never look back...except at the Q50 in my rear view mirror!

Lol Sorry I had too