thanks a lot for your advice. sounds very reasonable and considerate to me.
i am located in germany. i am getting used to the thought to rather prioritize quality over quantity and as you say buy quality gear step by step. the kef q150 seem very appealing to me. can you recommend any other decent coaxial speakers other than the kef?
i think i would rather prefer to stay with the slimmer, less expensive q150.
The main place to upgrade your Speaker choice is the Mains, or L/R channel. Center can also be quite demanding. These are where you want to focus your budget.
KEF is highly respected and while the Q series hasn't seen an upgrade in a bit, I listened to the Flagship Q950 many years ago and was reasonably impressed. Obviously, that is a large floor standing design vs a bookshelf, but the basic qualities are there throughout the lineup.
I'm not going to be much help recommending options to you in the European market. Other than being familiar with some of the brands, there is a big difference in what might be available internationally vs a smaller company producing for the local market.
Here in the US, there are many Internet Direct options that you likely wouldn't consider due to cost of shipping to you. The Hsu CCB-8 is a great example!
Of the European designers I'm aware of... Canton, Wharfdale, Monitor Audio, KEF, ELAC, Dali, Sonos Faber, XTZ... I can't say that any will really compete against KEF in a small bookshelf design.
You may find somebody offering decent on-wall Speakers similar to what I suggested as a potential option from Monolith, or the earlier mentioned Triads (another smaller US designer).
Regardless, going back to the recommendation that may make the most sense for cost and availability, I like the Q350 as it will afford better power handling and dynamic capabilities against its smaller brethren. Both are rear-ported designs and will benefit from being away from the wall a little, even though it looks like it may come with a bracket already attached which will put it very close to the wall.
This becomes a matter of trial and error for you as we cannot predict in-room performance.
Every room is different, so the behavior of that Speaker in your room would be different from me setting it up in a similar sized room...
Still, if you are liking the KEF options, look hard at their Center also. These will vastly outperform many other options in the market. In a small room, KEF will also greatly outperform any of the Polk's you mentioned.
End of the day, it will be about your preferences. It is your room, your ears, your ducats! But being smart about doing it can give you a much better system for the long haul then rushing it and getting it wrong.