During a boil water advisory that lasted more than a week we got a water drop brand RO system (the G3P800). It doesn’t have a tank but it instead uses a pump to do RO under a higher pressure so it outputs water fast enough to fill up a cup on demand, and a cooking pot if you’re not impatient. It came with a UV sterilizer, remineralization was an addon so we skipped it, especially since I prefer the taste that way and because I also use the RO water in our humidifiers and espresso machine where scale is a hassle. I’m a little biased because they accidentally refunded me so I got it for free, but it’s worked perfectly since we got it, and everything needed to install it was included (we just separately got a drain line adapter that lets us connect the waste line to the dishwasher drain so we could avoid modifying anything in our rental as the included adapter wants you to drill into the drain pipe). I have several TDS meters and the faucet’s included readout matches at usually 2-5, and I’ve used the water in my humidifiers 24/7 for months and still haven’t accumulated more than a couple days worth of regular water scale in any of them.

Oh and it also has a 3:1 tap to drain ratio which is nice.

I used to have a simple 3 stage under sink filter, so unfortunately I can’t really compare to other RO systems.