I know every once in a while someone hijacks this thread and says "the hell with 'Things You Don't Like'; How can you even have such a thread about such a great car?" and today... I'm afraid... I'm that guy.
I kept trying to think of things to post in here (although along the way I think I've posted one or two), but every time I tried to organize a post in my mind, I could only think about everything I love about this car. So, in the interest of being true to my actual response, here's my couple of things I ABSOLUTELY love about this car, followed by maybe a few downsides.
1) Come on, #1 with a bullet has to be, how great looking is this car? I just love the design of it. I love the way when I come around the corner and see it (alas, street parking for me) I'm amazed by the gorgeous retro looks. To me it looks like some British-Italian thing from 1966. I can easily see James Bond in this car. Or better yet, Austin Powers! Genesis did some promotional stuff at this year's Oscars, which mostly pissed me off because they had stars taking pictures with a car which was barely available in the US (and not at all in California) at that time. Blech. Genesis should bring Mike Myers back and do some ads with him and Heather Graham tossing this thing around some LA canyons.
Let's look at it. God knows I love to.
Jesus, that is one handsome car.
2) Following on point 1, how lucky are we that this car even exists? In this day of SUVs and crossovers, Genesis hired some folks from BMW and Bentley and said (so far as I can tell): "Go to town. Make the car of your dreams." That's just so cool. Rarely these days does a big corporation take this kind of chance and show this kind of creativity. It gives me hope for humanity, it really does.
3) I wanna keep this to 3 points so I'm gonna say... the tech in this car works great. I mean smart cruise, lane keeping, the map/navigation system, all of them really well done. 
Apple Car Play and 
Android Auto with a touch screen and no absurd and impossible to understand controller taking up the middle of the console! (I'm coming from a Mercedes GLC300; yes, I went from SUV TO a sedan... The GLC300 has not only a touch pad thingy but also a controller thingy, stacked on top of each other because IT refused to fire one of the two designers apparently). Plus the design of the dash controls such as climate buttons. They're all beautifully shaped and made and really intuitive. The complete opposite of the Germans. Let me tell you, I am so happy to be free of the German personality of "You will do it our way, and our way is the best, even if it makes no sense at all." This thing just screams respect for the customer from top to bottom.
Alright, in keeping with the thread, I'd better find some weak points.
1) Yeah, it's true, in comparison to the Germans, if you burrow beneath the surface you can find a few places where corners were cut. The gas cap is plastic and cheap. The wiper and turn signal stalks are plastic and cheap. There's no trunk closing motor (tell the truth, I can close the trunk myself and a motor is just extra weight and one more thing to go wrong, in my book). At first I sorta cared. Whoop de doo. I saved $10k (at least) over a comparably equipped Audi. I can live with plastic in a few places.
2) Probably my biggest issue as a huge music fan and car music lover is that the stereo really is a bit harsh in the high end (as you can find discussed in another thread in this forum devoted to the Lexicon system). But I will say it seems to be improving over time (though I've had the car a month and I'm only at 500 miles. Indeed, I drive very little.) and for anyone who has the same issue, try the "Clari-fi compressed sound file processor" setting to ON; it seems to be some sort of EQ adjustment that does smooth things out a bit, at least to my ear. And while I'm on this point I'm going to say I've been pleasantly surprised by how quiet this car is despite being much smaller and somewhat lighter than my previous car. The cabin is in fact a very peaceful place to listen to music.
3) Sure, I'd love to see a hybrid or electric version since that's the future, and rightly so.
4) Editing to add... okay, I thought of the one thing that has been the single biggest downside for me about buying this car, and that is having the dealer hit me with the "paint protection", "lojack locator" etc etc BS that I haven't dealt with in buying a car for literally decades. It got me down to hear with that stuff again (and what a contrast between those cheesy scams and the quality of the product), and I wish there were some way Genesis could convince its dealers to cut it out. But not a big deal. I'm a big boy and older and I know how to say no to that stuff.
Overall, I"m just so happy to have this gorgeous car that's also an amazing bargain and represents some remarkably courageous corporate decision-making in this era of bean counters and consultants armed with market research.