If you search for it, you can find some thoughts on the UNDVIKA but I found that certain benefits of the product were missing. I wanted to add them here.
The 0, 1, 2 ,3 wheel
The interface to turn on/off each unit is tied directly to the sensitivity level of the baby-phone. This puts this feature front and center which other baby-phones don't. In our particular situation, it has been super useful to be able to modify this setting super easily.
Portable
The unit is as small as it can get without it being unwieldy.
This is very useful for taking it on trips (vacation, grandparent's place etc.). More on that below.
For those of you thinking of getting a video baby monitor:
Those units tend to be much bigger.
If you do get a video product make sure that it does not use wifi. Otherwise you will be uploading video of your baby to the internet which is insane.
The battery life of audio only units is MUCH longer than that of video and audio.
As a parent, you should be looking to reduce the anxiety tied with having babies. Having a video feed of your baby only increases that. Let them sleep, spend time with your partner!
Easy charging
Although the contact charging feature is not useful and somewhat unreliable - the parental unit has a USB-C port which is what we use to charge. Also, you can just charge the batteries on their own!
Powered by normal AAA batteries
For some reason, all companies decided to use only built in batteries now. The flexibility of being able to replace batteries super easily is amazing. It's not just for replacing them when they are the end of their life, they can also be replaced by a fresh set that were previously charged. Effectively giving you double the battery life.
Overall, although it's surprising, IKEA made an excellent product with UNDVIKA.