I think it all goes down to how many GPD (gallons per day) you need, and how bad you water is. If you have hard water you R/O system will have to work harder than soft water.
As for brand names I would say Kent. Most people will only get one or 2 in a life time. So to say the one is better than the other is hard to say. I would think if you’re getting you second one it is because you need more GPD after you got more tanks.
The bad part of R/O is you can waste a lot of water getting everything set up right. You will need a storage tank to hold the water after it has been filtered. Depending on water presser you might need a booster pump.