I have and use both. Personally they are both great. If you like the lower maintenance of having cartos, then the liquinator is your best bet. Just fill and vape. I am using the 5.5 ml "phat" on my silver bullet. No leaks. No gurgle. No hassle with messing with juice bottles or having to check the carto to make sure it is wet. You still have the chance of the carto going bum on you and becoming a straw for the tank.
In comparison, my rio mini has better flavor with an atty. Cartos in general mute the flavor a bit regardless of how full you keep them. The rio gives me a little more hassle with fidgeting with the bottle and paying more attention to the juice to avoid flooding. However the flavor is quite a bit better. It is exactly like direct dripping without the mess and having to have a bottle of juice to fidget with.
Vapor production is about the same using lr cartos with the liquinator / lr attys on my mini.
So for me, less flavor but less hassle with my liquinator. Better flavor a tad bit more hassle with my rio.
Both are good devices for what they are made for.