I proceeded to purchase the Inventor Aria 12000btu after a lot of research, and it's true. This is the new version of the Aria, as there was an older version on the market (with quite good reviews as well). Initially, I wanted to buy the Gree Fairy, but with all the issues that have arisen with the distributor, I decided to choose Inventor. If you notice, this particular model has exactly the same features as the Bosch B1ZAI1250W, and I believe (just a guess) that both companies source them from Gree. The only difference is that Inventor offers a 10-year warranty, while Bosch offers 5.
Also, for a 12,000 BTU unit, it has very good performance - it reaches 14,200 BTU in cooling and 16,300 BTU in heating!! In terms of energy consumption, it also has very good performance, as the SEER 7 and SCOP 5.1 values are quite good.
It covers an area of 25 square meters (living room, hallway, office). With the other doors of the house open (bedroom and kitchen - 25 square meters), it simply spreads the cool air to those areas mainly because the air doesn't have easy access. However, if I "push" the cold air towards those areas, for example with a fan, then the whole house cools down normally.
Despite the poor insulation of the house, the outdoor unit is not audible at all, and the indoor unit is barely audible in Silence mode. In turbo mode, it sounds like a powerful fan. I consider it to be at a good noise level without causing discomfort.
It came with the Wifi module, which, however, was not connected to the indoor unit, and there is no installation information for the Aria model on the Inventor website. But if you notice, in one of the user manuals, there is a diagram showing where it connects. You don't need to unscrew anything, you just open the front cover and attach the USB stick to this accessory that connects to the screen. Then you should make sure that your phone is connected to the 2.4GHz band and not the 5GHz (for those who have 5GHz as well). The good thing about Wifi is that it also tells you the outdoor temperature.
You will need to register the serial numbers of the units on the Inventor website for the warranty to be valid.
Overall, I want to test it further, but the initial impressions are good. I consider it to be a value for money air conditioner.