I got my tootle puffin wife a kanger subtank mini to help wean her off the protanks she has been using for the last 2 years. Set up her RBA to a 1.6 ohm 30 gauge rayon coil and so far (3 weeks) its been a great atty, no leaking, gurgling or any problems at all. I haven't used a stock factory head in almost 3 years so I'm not going to start now, but I haven't heard her yet concerning any subtank issues. I can't comment on a leaking factory head since I won't use them.
She vapes a cotton candy blend I make at 12 watts on a Istick50 so her juice is IMO a bit sweet but she can vape almost 2 weeks on a build before it poops out.
If you don't know how to rebuild attys, now is the time to learn, the subtank is easy to rebuild(easier than a protank) and so far its got a gold star from me for ease of maintenance and a thumbs up from my wife for vapor production. She's finally realized how muted the protanks flavor is compared to the subtank.
Just once in a while take it all apart, clean the orings and grooves (hot water for the rings, Q-tip and isoprop for the grooves) and be sure the glass tube is true and seated nicely when putting back together.
I'm just waiting for my 2nd subtank so I can play with the OCC and vertical coils to rebuild them without having to use my wife's atty. I also have a couple TFV4's with the single and dual RBAs on order in a coop and really looking forward to those hitting my mailbox, those attys are mine, but its still my kayfuns that lead the pack in my books for a quality vape.