I am in the process of getting rid of my Stinger. I can justify it based solely on the dealership experience (maintenance). Many will not agree with this sentiment because they are very pleased with their car and their dealership for a number of reasons. I have been let down by the car and the dealership experience.
I left a Lexus "F" car (not F sport) for the Stinger because my ISF was getting older and I wanted some of the characteristics you mention above. I was looking for a larger sedan (up from the ISF size), RWD, 350+hp, modern electronics/infotainment, and warranty. My first choice was a GS-F, but the cost (new) for that car was ridiculous and the GS-F CPO market wasn't that well populated at the time, so the list got whittled down to the Kia Stinger. I made this choice partly due to two positive Hyundai Genesis ownership experiences. I was very excited about buying and driving the Kia Stinger based on the hype at the time. Then the issues popped up, many of them. To compound the problem, Kia didn't have a fix for them.
Obviously, this is a Stinger forum and one that I have been a proud and participating member of. I am not here to bash or "pile-on" the Stinger, nor will I. I will simply say that my ownership and driving experience with the Kia has come nowhere close to the experience, effort, and car put out by Lexus. It is not even close. I have owned 1 Lexus and 3 Hyundai/Kia vehicles. That should indicate that I have no bias against the Hyundai/Kia brand. I just don't feel that they are where Lexus is currently with overall ownership experience.
If you are interested in Lexus, as others have said, stay away from the mundane offerings (grandpa cars). The F-sport cars are appearance only packages and will be a HUGE letdown compared to the Stinger (unless you add a supercharger and suspension/brake
mods). If you should choose to go with Lexus, I strongly encourage you to choose a CPO GS-F. Good examples can be had in the $45k to $50k range with a 6yr/unlimited mile warranty. FWIW, you won't need the warranty in my experience. There are road going supercharged GS-Fs with 800hp for anyone questioning the potential of these cars or dismissing them as old people cars. The first :40 seconds will illustrate (
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For those who love/like your Stingers, I am glad for you. I wanted to be one of those people too. Had Kia done their part to earn and keep my business, I would still be a fan. However, the OP was asking for input from Lexus owners/shoppers, so that is what I tried to provide.