I prefer the new Riva 510 made by Eastmall because they are 3.7v (Ego is 3.4v). The Riva 510 kits at Liberty-Flights.com are all new stock from Eastmall and 3.7v. The loose Riva 510 SE batteries are 3.7v. Any other loose batteries may or may not be 3.7v. If you shop there, first press 20% off upper left front page, then shop at the lowered prices. I see no reason at all to buy a Riva rather than an Ego if you are not getting a 3.7v Riva.
3.7v is important to me because I also use slim models and I want the cartos to as warm or warmer on the big battery.
As for Ego-T, some like tanks and some do not. If you buy Riva you could buy one tank atty and tanks and try that on it to see how you like tanks. I prefer to use cartomizers and keep my main flavors totally separate and not blended in an atomizer, I also don't like the bother of cleaning and replacing atomizers, and tank atomizers are more expensive than normal atomizers.
3.7v is important to me because I also use slim models and I want the cartos to as warm or warmer on the big battery.
As for Ego-T, some like tanks and some do not. If you buy Riva you could buy one tank atty and tanks and try that on it to see how you like tanks. I prefer to use cartomizers and keep my main flavors totally separate and not blended in an atomizer, I also don't like the bother of cleaning and replacing atomizers, and tank atomizers are more expensive than normal atomizers.