Drives well, but some features are problematic
I have no complaints about the way it drives. Acceleration is great. Steering responsiveness is good. Driver's seat is comfortable. Controls are relatively intuitive and easy to use. Sound system sounds good.
The turning circle is pretty wide which makes it not the easiest to park in congested parking lots, and hard to make U-turns on narrow streets.
I have issues with some of the driver convenience and safety features. I have a Honda CRV (2017) that has some of these same features which I find useful, but on the Ioniq I find them much more sensitive and not useful - or distracting - for that reason. Your feeling about these may vary somewhat depending on driving style - here's my experience:
* Lane keep assist seems to want to keep me right in the middle of the lane. My habit is to drive towards the right edge of the lane, away from oncoming traffic. I find that it fights me more than I would like so I have turned it off. I would want it to only alert me if I am actually leaving the lane.
* The scope of blind spot detection is too wide. The only real blind spot in the vehicle just off the rear bumper on the drivers' side, but even allowing that it can also be useful to have monitoring on the passenger side, the "blind spot" zone extends well back past the back of the vehicle on both sides, and doesn't seem to update very fast, so that even when I am changing lanes after passing a vehicle it can sound an alarm and try to steer me back into my lane. I temporarily turned it off but that turned of the blind spot indicators on the side mirrors as well, not just the alarm and corrective action, so for now I have decided having it on is the lesser of two evils.
* It will sometimes sound a collision warning when I am going around a bend in the road and temporarily facing towards a car parked on the side of the road
* The stability/traction control seems to kick in when I go over a small bump or pothole, making me wonder momentarily why the vehicle seems to have lost power
A few other issues with the tech features:
* You can set the level regeneration you want to kick in when you take your foot off the accelerator. I like to keep it at 0 so the car will coast when I take my foot off, like a traditional non-EV. But, for some reason, while it will remember the last setting for levels 1, 2 and 3, it will not allow you to start in level 0 when you start the car, so I have to change it back from 1 every time. It also won't let you change it while in reverse, which is just another little annoyance.
* I have disabled the feature that automatically unlocks the car when you approach, since it would unlock any time I went into my driveway, even if I wasn't getting in the car. I believe the doors will at least automatically relock after some time if not opened, but I still find it annoying that it's constantly unlocking and locking.
* Worse is the automatic trunk opening. This is supposed to open the trunk automatically if you're standing next to it, if you're trying to put something in but your hands are full and you can't open it. But it's far too sensitive - especially when using a digital key on my phone. I can't stand within 4 feet of the trunk without it starting to beep to say it's starting the opening process, and more than once I've had it open while just walking past the car on the way somewhere else.
* Automatic highway lane change works as intended, I guess, but I have that turned off as well. It will automatically steer the car into the next lane if you put the indicator on and it's safe to do so. But it's pretty conservative, and it can't speed up or slow down to pull into a gap in traffic, so it's really only handling the easy lane-changes, which were easy anyway. But if you start to make a lane change that it can't make itself due to "conditions not met" then it will beep at you to alert you, which is a distracting thing to happen in the middle of a lane change because you don't know immediately if it's just "conditions not met" or a blind spot warning or a collision warning. So I find it safer to keep it turned off.
* Built-in navigation is bad. The look of it is OK, but it consistently gives me much worse and slower directions than Google Maps.
One more dislike: The low-profile door handles are annoying for a couple of reasons: 1. they're less ergonomic than a handle that you can just reach out and pull - both because you have to unlock the car first and wait for it to pop out before you can open the door, and also because it's harder to hold and pull on a "stick" than it is on a curved handle attached at both ends. 2. It means that if your car is unlocked that information is being broadcast for all to see by the handles sticking out. It's an advertisement for any opportunistic criminal who wants to see what they can grab from your car.