Haven't found a juice that matches the OG mango pods but I have a few in rotation that I like. I do miss the brief Cambrian explosion in third-party pods, before the FDA decided that "the youf" should switch to disposables, but at this point I'm just grateful that Juul is still in business, it's pretty much in a class of its own.
I'm also grateful juul is still around at all, I haven't found any other device with such a nice small and flat form factor. Everything else bulges out of my pockets
The latter isn't much like OG mango, fair warning, but you'll probably like it if you were a fan of the old school.
The trick with refilling is to press the sides in when replacing the rubber stopper. If you do it right, you'll see a bubble or two rise up from the bottom. If you skip this part it will leak everywhere. Also, blow through the cart several times to clear the tube. It's a bit fiddly at first, but you'll get the hang of it.