Which central ventilation system?

I would choose the system that best fits my house regardless of the manufacturer... if all the above mentioned can move the desired air volumes, then the one that offers the most comfort, for example moisture recovery.

Without more information about the house and the systems, it won’t work, because they all have different systems in their range.

You don’t say I am going to buy an Audi or an Opel today, no, you say I am going to buy an Audi A4 or an Opel Corsa.

I thought that there might possibly already be advantages from the brands themselves, or one can see differences that can be directly compared.

It should be about a 120m² house, although that doesn't really matter right now.

I would just be interested in why someone tends to prefer one brand more or less.

I think some manufacturers have advantages like a web interface or mobile app, which some, for example, do not yet offer.

Brand loyalty or tendency is usually subjective... regardless of the quality of the product, whether one needs the app or similar for satisfying the gaming urge is rather secondary as well. For the proper operation of the system, no apps are required

I would rather pay attention to things like: Can additional sensors be connected to the device? (VOC, CO2, humidity) How loud is the device? What is the power consumption? Do I have to use expensive manufacturer filters, or can I cut them myself from the roll?

The manufacturer then doesn't really matter... what is important in this context is that the installer has to know the device...

Mycraft has already mentioned many good decision criteria. We faced the same question. Although I can understand that controlling via app/web is important to some. That was also an important point for me. In the digital age, I expect that to be possible. But yes, it should not be the decisive criterion. For me, energy efficiency was still a very important point. After all, the device runs 24/7. I was also choosing between Hoval, Pluggit, Zehnder, and Helios. Ultimately, Helios and Zehnder made the shortlist because of efficiency, quality, and usability. Now it will probably be the new Zehnder ComfoAir Q, which will be released in summer. My heating installer mainly installs Zehnder, which also made the decision easier. Incidentally, the new device can be controlled via app and Zehnder (supposed to be identical to [PAUL]) regularly scores well in energy efficiency.