Some of CA Curmudgeon’s comments sound like he’s talking about a pre-2016 RX350.
On my Wife’s 2016 RX350, I agree that voice command doesn’t work very well and the optional winter front floor mats were obviously designed by a committee of lawyers. If Lexus isn’t willing to offer functional floor mats, they just shouldn’t offer any at all.
My major complaint is with the over-priced navigation system, which we didn’t want to begin with. It frequently suggests routes that are NOT efficient. When engaged, the map itself is usually accurate, but the verbal and text directions are often 180 degrees wrong. When I brought this to the attention of the dealer’s service department, they suggested I buy an update, with NO guarantee the problem would be resolved. This has spooked my Wife to the point that I bought her a Garmin nuvi 2599, with lifetime updates and traffic and that’s what we use in lieu of the built-in.
I’m not sure the frontal Pre-Collision System works. The dealer was not willing to do a dynamic test.
The throttle on the RX 350 has a .O6 sec documented delay. A dealer diagnostic tech hooked up a data collection program to the vehicle and was able to graph the "Dead point delay". The case was sent to the factory techs twice and was acknowledged as "Normal operational standards". This effectively removes the drive active control of the throttle. I have never driven a car that does not respond to every impulse I have while I operate a car. Wireless deadbanding is "Not" the hallmark of safety. You can't have any human controlled machine set to not respond to instantanious correction. The car is never allowed to decide when it wants to add or subtract power. The driver is suppose to be in charge. This is grossly unsafe.
The car is generally great. Reliability is the big seller to me. My complaints are about several minor areas, where Lexus has missed the mark completely. Example: each door in the front has a swing out pocket. The problem is that when the pocket is swung out, gravity rearranges the contents of the pocket such that it can no longer be closed. My model has a dash mounted cup holder along the lines of what used to be an ashtray. The design is such that you cannot put ANYTHING into the compartment and close the door. Pretty much useless except for cups. The center console lid doesn't fully swing open, thus making access difficult even when stopped. My car has utility outlets below the center console liner. So I use an extender cable to get the outlet where it can be reached. The overhead switches for interior lights, garage door openers, etc. are flush. Thus, you cannot easily find the buttons by feel. I find the voice commands for bluetooth phone, etc. to have much difficulty in understanding a voice. The climate control system is downright strange. It requires a lot of fiddling to turn A/C on/off to maintain comfort when setting a fixed temperature is supposed to do the trick. The driver's floor mat doesn't cover the carpet where your left foot rests, thus causing unnecessary wear. NOW for the biggie, which will influence my future buy of Lexus cars. The car comes with a "funny spare" (compact spare). That causes any problem with a tire to go from an annoyance to a trip ruining experience. The compact spare has a top speed of 55 mph. That's quite dangerous on western state freeways. And on drives such as Los Angeles to Las Vegas, there are few places to have the tire repaired. Now the worst part: the full sized flat tire will not fit into the space the compact spare occupied in the trunk. Thus, you will have to move luggage into the back seat or strap it on the roof rack. I realize that many other cars are using compact spares, but I would expect a luxury vehicle to not cut the corner so carelessly. Finally, for a premium car, I would expect a better audio system. If an optional premium audio system is offered, it should be bought. In test driving newer models of the RX than my own, I find most of the complaints have not been resolved. The car is comfortable, drives well, and handles very nicely. It is a bit bouncy going around a corner if there are bumps in the road.