To answer the OPs question, out of the 2 selected, I would go with the Bloog Maxxfusion.
The Bloog kr808-d1 with Cartomizer vs a Riva 510 using carts is a no brainer to me in terms of ease of use. The Bloog comes with cartomizers, and the Riva 510 lite kit comes with 2 atomizers and 10 carts. With a cart and atomizer setup you will be dealing with
juice leaking, inconsistent juice feed and occasional dry hits, not to mention the problems you will experience if you get the atomizer too hot.
With the Bloog and a two piece system, you don't have these issues. Plus refilling a carto is very simple and virtually hassle free compared to refilling a 510 carto.
On the downside, Battery life is shorter than the RIVA. But thats what the PCC is for.
Now, some people have recommended the Volt which I also own and use along with the Bloog. Some people say its the same because they look the same, but I must disagree based on my own findings.
If I fill both a blank bloog carto and a blank smokeless image carto with the exact same
e-liquid (BWB Malty Toffee 30pg/70vg) and vape it, it tastes different and battery life is different as well. The Bloog carto ohmed out at 2.66. Battery straight off the charger at 3.71 and under load at 3.61. The smokeless image carto ohmed out at 2.15. Battery off the charger at 4.29 and under load at 3.6 The battery on the bloog lasted a little under 2 hours. I got a little over an hour out of the smokeless image volt. What is even stranger is that there were no wicking issues with the volt cartomizer, But with the Bloog I would get an occasional dry hit under the same approximate usage.
The Bloog and the Volt may look alike, but in my opinion, do not perform the same.
The volt is a decent kit for the price if you choose it as an alternate to the Bloog.