After using 2 different models of Eleaf PICO, (original PICO, then PICO 25) I have been smoke free for 3 years.
Recently shifted to POD device (SMOK Novo2) about 8 months back, for the convenience mainly, and shifted to nicotine salt 35mg liquid along with it.
Highly recommended POD devices for older vapers who don't want to deal with lugging around a whole vaping kit in a bag, and don't mind paying 30% more (approx) for 3000% more convenience.
The one I use, the whole tank and coil are refillable, and a single unit. Once coil is dead, chuck the whole thing and fit another. Using nic salt means you need very low power, so its on board small battery lasts whole day, and is easily charged with any micro-usb cable, so the whole charger & cell thing is avoided. Not for cloud chasing though, because of low power, but with this it becomes very inconspicuous, can vape in crowds without anyone noticing,
I ordered from aliexpress with an estimated years worth of pods. Previously I got my PICOs and their coils from aliexpress as well. The trick is to estimate usage and buy in bulk in a single shipment every 6-12 months,