I think I read Riva and Ego are more like 3.4v. I definitely get a slightly warmer bigger hit with Riva + standard res carto than with the same carto on 510 (3.2v)
I didn't know about the Riva SE - interesting
Re carts - most people get tired of carts pretty fast. Save them though - they are good for testing or vaping juices you don't vape enough to give their own carto. Drip tip is also good for testing. You can get nice precut 510 blue foam stuffing for 510 carts cheap at strictlyejuice.com. It's a stuffing that holds its shape, rinse clean under running water, pats dry easily between paper towel.
For the juices that I love to vape I use Boge cartomizers. I vape both Riva and slim manual 510 so I use standard resistance Boge cartos (slim 510 can only use standard). But Riva can also use the more power-hungry hotter LR 2.5 and 2.0 ohm Boge cartos. Boge are the favorite cartos of most people.
If filled properly, allowed to settle so every bit of stuffing gets damp (I lay on different sides for 15-20 min), and kept damp by adding juice before you run it too dry and singe it, a Boge carto can often perform well for a week or more. I don't try to clean them for further reuse. Sume people succeed with that and some do not. I do save them and may try to clean some at some point.
