Sort of unrelated but here's some oldschool RTAs with shorty topcaps and rotted out acrylic (threaded) sections..lol..I think they only held maybe half a ml of juice each haha..Orchid and Kayfun clones...and also an eGo+eVod...who needs a "pod" vape?
Ok don't go making fun of my Evods.

I usually DTL (semi-restricted) but I still have like a dozen of those Evods. Those are a great little stealth vape on a pico or the like. I build them to around 2.2ohm and run 12-18mg nic in them and they are great. Yeah, only hold a bit of juice, but they last a LONG time with that build and nic level. Those Evods are great to have around.
I like the Siren 2 wide open as well. It's a solid vape for me, hope you enjoy yours.
That said, I also am a fan of the Serpent SMM. Run that wide open as well, definitely a different vape than the Siren, but I enjoy them both. Main leaking I get from the SMM is after filling. Screwing down the top cap can increase the pressure and push juice out the airflow. What works for me is after filling, I give it a good few pulls right after tightening the cap down. This seems to vape off the juice pushed up through the cotton and keeps it from leaking. It's a good vape though. Depending on your coil (heat capacity) and vaping style, you will of course get the obligatory condensation from the bottom airflow.
I've got the Zeus as well, but seem to keep going back to the Serpent SMM the most since I'm very familiar with it. I'm sure the Zeus will be enjoyed as well once I get around to it.

. Been squonking a bit, so my RTAs are getting ignored for the most part currently.