We have Kinetico for ours and I have it only hooked into drinking tap and ice maker.

You may get more helpful replies if you share your water analysis. If your water is so bad that you think you need RO for the whole house, reputable local water treatment pros should be called in to discuss options. RO makes more waste water than treated water and is generally used for just drinking water applications. Our well water has a pH of around 6 so we have a whole house neutralizer. It's borderline for hardness and we're choosing not to treat it due to regulations here requiring a dry-well for backwash for softeners. The equipment for the neutralizer as well as softeners is somewhat generic: tanks filled with media, topped by electronic valves that cycle. Different pros prefer different valves and Clack is often highly regarded. You don't say if you plan to DIY, but addressing a whole house system involves plumbing, drainage, calculations, etc. If you need that level of treatment, local referrals for good service is the way to go and they will want to use what they prefer. For RO drinking water, many systems are designed for DIY. A basic system is not hard to do if you can put it under a sink. The most 'invasive' part of it is to drill a small hole in your drain for the RO waste. There are various options to add that can make the install more involved. We had two quotes for an RO installation, $1200 and $1400, simple system, no electricity involved. You can buy the equipment ranging from about $2-300 (for basic no pump or UV). My husband wanted to do the installation. I did a lot of reading, watched videos, shopped around and ended up with an iSpring PH100. This particular model claims to use a RO membrane that has a 1:1 waste which is much better than most. It also has a remineralization filter. If you DIY, the documentation for the iSpring install is bad (parts look different than the printed instructions, tubing is not color coded, it didn't address the final filter, not intuitive for first timers). I found a couple of youtube videos that were extremely helpful. I watched them many times before I directed the husband step by step. You need to really familiarize yourself with how the water flows. iSpring has excellent patient helpful customer service. Despite the poor instructions, I think it was the best for us and recommend it for a patient DIYer that's willing to prepare thoroughly. Most RO systems have basic housing and tubing. Some have quick release features, there are slim line products, other conveniences, but just read about the actual filters for what they claim to remove. Be aware of the level of waste water from the RO membrane. Also be aware of the longevity of filters/capacity, access to replacements, and cost of the filters.

My experience is that many water filtration systems are quite reasonably priced, but require annual or more frequent filter changes, so when looking at the time, the cost of replacement filters may be the most important point. Look for popular brands, so the filters will be available.

It gets tiresome answering the same questions: You can search on here and save everyone a lot of work.

Asking what brand of water treatment is like asking what brand of medication that people are using because you were thinking about taking some medication. It really is about how wrong-headed it is.

Water treatment should be based on the actual issues / contaminates that you have in the water. Once you know that, we can suggest some treatment methods. Otherwise you are just flushing money down the toilet - and there are MANY companies selling water treatment that would be happy to help you with that.