What a coincidence for this thread. I'm still new so I don't claim to know what I'm doing or talking about but I'll share my experiences.
I started off with Reos so I had no experience with anything else. As someone once told me, by doing so I took the
fun out of all the wasted money with mods & time I would have experience before getting the Reos. I started off with Cisco atties. It was a bit of of a learning curve squonking them to avoid flooding & dry hits. Tried eGos & a Provari that my buddies had, nothing spectacular there for me.
Now I only use RBAs, only learning curve for me was playing with different types of coils & wicks. I have a bunch of Phoenix v4/Octopus/RDA style RBAs. I was worried about leaking since I pocket carry so I spent the time modding one for bottom air feed. Rob commented that I would probably end up liking side air better & he was right, the side air feed works so much better. My bottom air feed mods work well but not as good as side air & I haven't experienced any leaking as I assumed I would. The RDA clones are no RM2 but after they come off the lathe & mill, they have been just awesome for me. I've built a number of different configurations with them & so far I haven't had a build that I wasn't happy with. Very reliable & no easily overflooding them like with the Ciscos. I love them but again they do need just a bit of machine work to work properly in the Reos.
So then I wanted a cheap mod to use with a dripping RBA to test new flavors & to use the Kick that I bought that I intended to use with the Grand. Forgive me oh great Lord of the Bottom Feeders for I have sinned as I had purchased a non-Reo mod after the Reos.

I have heard great things about Gennies so I picked one up too. It may just be me but I find they aren't too forgiving.
My first build was with 500 mesh, 30 awg, stock air hole. Very disappointing. I vape VG only so the 500 just doesn't work for me. I don't like airy draw & I don't draw straight to the lungs but the RSST really needed a bigger hole. Drilled out to my usual #56, still disappointing, then 1.25mm, now too airy & still disappointing. Finally my 3rd build I was getting somewhere, 300 mesh, 28 awg, sub-ohm, great flavor but still not happy with vapor & TH. I'm on my 5th or 6th build now & it's getting better each time but it's still doesn't compare to my Reos with the RDAs. My Reos at 1.5 ohm are still so much better than this Genny has been so far. Even my very first RDA build was better than what the Genny is now. I haven't gave up on it but I have a feeling I won't be happy as I'm just expecting to get that same performance as I do with my Reos.
I haven't even had the thought of bringing this tube mod & Genny with me out the house, no way it would take the place of one of my Reos, I'm not sure anything else will, it's just not for me. I now know I'm a bottom feeder person & a Reo addict. And the Kick is now sitting back in it's it little plastic box. LR-SLR for me, if I'm out & I'm starting to loose voltage, I just pop in a fresh battery.
Everyone might have a different style of squonking, at least I do. Once you get that down, IMHO bottom feeders seem hard to beat. Bottom feeders might not be for everyone but I personally really don't think I could find a mod that I like better than a Reo.