Ok, so now you want advice on the tank to get as you decide on the I Stick 50w RIGHT? Here are my recommendations:
Joytech Delta II: An amazing clearo, 4ml of juice, organic cotton in the coils, the flavor is a bit better then the Subtank Mini IMO (might just be because it can handle higher wattages which I like) and it is rated for higher wattage then the Subtank. I vape it at 50w daily with VG juice and haven't gotten a dry hit, I turn it up sometimes (I don't go past 70w) when I want to get rowdy and again, no dry hits. The flavor on this clearo really impresses me and I wont say its leagues ahead of the Subtank Mini because its not HOWEVER due to the fact it can handle higher wattage without getting dry or burnt I will give the slight edge to the Delta II. Also you can buy an RBA head for it and it really gets rowdy with a .3 24 gauge ohm coil in there and the AFC wide open. I mean it chucks crazy clouds set up like that, bigger clouds then some of my "cloud chaseing" drippers with the same build. The airflow is nuts on the Delta II, I close it a bit more then half and it is still a really airy draw so that should tell you that wide open its nuts.
Subtank Mini: A great clearo as well, the flavor on this at low wattages amazes me. The fact that I can vape it at 25w with the .5ohm head in it and still chuck some clouds and get a really impressive flavorful vape really makes me happy. It hold a bit less then 4ml I think. The airflow is not even close to the Delta II but I still like it, I like it wide open and that for me is almost bang on my type of draw. It COMES with the RBA head HOWEVER I do not like this thing in RBA mode. I feel the design of it really chokes off the airflow and personally I would just prefer the OCC coils. The coils on this clearo are straight up organic cotton which like the Delta II is all I want to see now n days. If you prefer a lower wattage style of vape this is your guy IMO and I really like the fact that I use a lot less juice in this then the Delta II due to the lower wattages and so forth HOWEVER I dislike the fact that it cant handle the higher wattages but whatever its not a big deal.
The Lemo: What can I say? If your alright with building coils I would say get this and don't look back. I had mine sitting around not in use for a long time but just re built it last night and again this morning and it really is amazing. The flavor, the vape production, the capacity, the airflow, the looks and the price are all bang on for me. I love that I can have one with a .8 28 gauge at 40w and another at .3 with 24 gauge at 60w and never get a dry hit. It chucks come serious clouds with the .3 build I put in this morning (rayon) and the flavor is better then the above options IMO. Once I got this setup how I like it I feel in love all over again. It was like when I first touched a Kayfun (not in performance but just in the sense of "omg I need five others for all my devices and all my different favorite builds") Lastly the price on this bad boy is amazing. Grab two, some different gauges of wire, some cotton or rayon and your still looking at less then $100.
Conclusion: In my opinion I conclude that if you are fine with building coils and wicking them and so forth then you get the Lemo. If you like a lower wattage vape and don't want to build I say get the mini subtank and lastly if you like a bit higher wattage (40-50w IMO it shines best) and want to also have a good (IMO) build deck get a Delta II. I hope I helped and if you need anything else please PM me. I own 2 Lemos and my wife owns one. This morning I ordered her another so she could have one with a low ohm build and the other with a higher ohm build. I also got myself three more to bring my total number of Lemos to five. I only own 3 Delta IIs and 2 Subtank Minis. That should show you two things: one, I am insane and two, I like the Lemo the best.
I wrote all that to go back and read you got the Mini. Oh well, great decision and in future you can refer to my post if it may help you. I still enjoyed writing it lol.