As far as another small pod set-up (even smaller than a Juul)...IMO, the JustFog Minifit pod set-up is a really good one. Quite a few of my friends love them, too, as well as many ECF members. Most of us have bought a "stash" of the starter kits and packs of the replacement pods...because they're such a great pod system set-up. My friends and I all use our regular strength eliquid in them (3mg/mL - 15mg/mL), not the salt nic eliquids that are much higher mg/mL like in the Juul and many others that are pre-filled. Anyone can use whatever strength he/she wants to in them though.
They come in 2 versions now: The Original one - is only 70mm long x 21mm wide x 15mm thick, and has a 370mAh battery in it. The pods come in a 3-pack and can be found on sale sometimes for $5 or less per pack. The capacity of each pod is 1.5mL and they have a 1.6ohm coil in them. The pod is refillable, and it's easy to do that. There are You Tube videos that even show you how to rebuild the pod with a new coil and cotton, if you want to do that. I still have my first pod that came with the kit, in use, and it's been a long time. The Minifit isn't my main set-up, but I take a few hits off of it each day, and it's my "go-to" set-up for quick trips into town, etc. There are several members though, who have mentioned that either they, or their spouse, use a Minifit as a main set-up. They just have several in use at a time, usually with different eliquids in the pods.
The 2nd version of the JustFog Minifit is the Minifit Max. It has a 650mAh battery in it (so it lasts much longer than the original one, before needing to be charged), takes the same replacement pods as the original, and therefore has the same capacity and same 1.6ohm coil in it. The size is about 1 1/2" longer than the original, and it gives the same great vape, IMO.