kold Ster-il filters do they work well?

[LS90gal]

Hello everyone, I am new to the forum. I am looking to purchase a water filtration unit. In the past I know that my LFS used kold ster-il units, which they had great success with. I like that there is no water wasted not like with RO UNITS. Is anyone out there using Kold ster-il systems or RO/Di is they way to go.