Is Carrier a good air conditioner

Good morning!

I would like to have air conditioning installed in my living room, but finding a suitable air conditioning technician is a bit ... complicated.

Briefly the rough key data:
25m² living room + 5m² eat-in kitchen
approx. 5m ² window area to the south-east (only illuminated until noon), of which 4m ² double glazed, 1m ² single glazed (cat flap)
ground floor

The AG is to be installed standing on the balcony, a core drilling through concrete is necessary for this.
From the AG you go up the wall, through the hole and there is already the IG - all in all, short distances.
Condensation drains off over the balcony floor - I have boards with a substructure, underneath the water can simply drain away.

It is very important to me that the working group is as quiet as possible so as not to provoke anger.
Furthermore, a few features such as timer, air filter, app control would be desirable.
I would want to spend around 2500-3000 euros.

In terms of feeling, I prefer a Panasonic system that feels best for my criteria.
I'm keeping an eye on the CS-Z25VKEW / CU-Z25VKE from the 2019 catalog or the CS-Z25TKEW / CU-Z25TKE from 2018 (?)

I have already written to two technicians, one of whom did not answer at all, the other at least came over.

He said it had to be 3.5kw, which I find not entirely implausible (I have quite a few electrical devices, in total approx. 1.1kw).
However, he only installed Carrier and Toshiba, Panasonic was technically too outdated for him and Mitsubishi "too electric" - he would have to wait 3 months for new circuit boards. Sounds strange to me, but that's what he said.
Toshiba has its large headquarters here in the city, maybe that's one of the reasons for its limited selection.

I now have an offer for a "Carrier" air conditioning with 3.8kw.
Equipment, installation including core drilling and acceptance would cost me around 2200 euros.
I could upgrade to a "top" device for ~ 600 € more - no idea what one, possibly Toshiba.

Now I haven't heard anything about "Carrier" up to now, Toshiba seems to me much too expensive for the features it offers compared to e.g. Panasonic. All in all, I don't feel comfortable with the offer because it doesn't correspond to my preference at all - it probably makes you just as cold, but nothing else, I don't know the brand and the thing doesn't have any real features either.

tl; dr:

I now ask three questions:
  1. Has anyone ever heard of Carrier, is that any good?
  2. Panasonic seems to me to be pretty cheap with the features it offers compared to e.g. Toshiba, how come? What is the catch?
  3. How do I find an air conditioning technician who installs what I really want to have - the websites of the air conditioning companies usually don't offer much. I come from Düsseldorf.

Thank you for your feedback!