For me, I've been doing rda and rta for years, wanted to come up with something fairly modern in case I couldn't do builds. My preferred ohms are around 0.4, so I wanted something with good coils in the 0.3 - 0.5 zone.
Vaporesso gt ccell were an easy pick for me, due to many reports on excellent flavor and longevity, and that particular format meant a whole lot of other heads were compatible. The tanks fell out - Hellbeast as a highly regarded new tank, Cerberus due to buying an Aegis Solo in kit form, NRG as a known compatible at a good price, NRG SE as part of the excellent tarot baby sale.
Tanks will have different failure modes, items that wear. Basic orings are a no brainer, but the various seals/fill mechanisms can be more of a hassle over time. I purposely went for multiple models, am quite confident that in the event I can't build I'll have more than enough tanks to use with my several year supply of heads.
My long term vaping is all about rda and rta, especially rda. The ones I have should last many years, especially given most of my vaping is squonking.