You really need to understand weather compensation and its benefits. You are trying top justify your lack of knowledge on the topic.
I understand wc and the benefits perfectly, I just don't think the financial savings are interesting in a standard domestic situation; what's a tenner per year?
...which will rot in 15 to 20 years.
I put inhibitor in the systems I install, AND make sure it stays topped up; no rotting in 15, 20 or even 50 years.
You are implying weather compensators breaks down. They rarely do.
I did not imply anything. I am STATING that they CAN break down. IF they do at any time outside the warrantee period, but inside 15-20 years, the break even point financially moves to about 2 decades. That is simply not a safe investment in terms of return.