I suggest that with any type of water treatment, you need to learn/know what you need, as opposed to what you want. Otherwise you can quickly become a victim of sales people/hype.
Visually, we can't see particles less than 50-45 micron. The lower the number the smaller the particle. So why filter invisible 'dirt'? It won't harm you, the vast majority of appliances, including softeners, or well pump pressure tanks.
So really, what good are these disposable cartridge type filters, that are being misapplied as "whole house" filters, when they were never meant to be used as POE (point of entry) treatment? And if you ever get a BB 4.5" x 20" housing and cartrdige and replace the cartridge once after beoing installed for say 6-12 months, you won't want to do it again. It's very heavy and dirty and you unscrew it and take all the weight, it is filled with water,,, thereby difficult to do without dropping it and breaking the sump. And people won't change their much smaller types on schedule although it is not hard at all...
Unless you have a Kinetico packed resin bed upfow service softener, or an upflow AN filter etc., you don't 'need' one. And I say you shouldn't WANT one either. I say that based on my 19 years of water treatment experience with thousands of customers and reading/replying to many more thousands of posts like yours nickyg.
If the cartridge is getting yellow to orange reddish brown, you have an iron and/or manganese, maybe H2S, problem, and no disposable cartridge filter of any type or size will prevent them from going right on through it, to still cause problems.