So RTA, its like a rda where you make your own coils yeah but has the benefit of using a tank so you dont have to keep opening ur rda to drip juice on as i never could just drip down the hole when you take the mouth piece off. So yeah erm that appeals to me as it means i dont have to buy ready made coils as im comfortable enough now at making my own 27 kanthal a1 i think it is coils which come out about 1.4ohm. Would getting one of these be good for me. If so is there any good ones for about £15 max thats easy to use and keep clean and doesnt leak as in leaks to where the bottom where it touches the battery connector like my naut mini does which i hate when it happens, dont think it ever did that with the magma clone i have. Needs to be really good at tasting flavs tho not just tasteless or mild tasting clouds. M2L user btw.
Sounds like you need a Kayfun clone my man! I've only used the Mini V3 and the V5, though they're basically identical, the V5 is just a scaled up, slightly improved version.
I got the SXK Mini V3 from Fasttech and SJMY V5 from 3fvape, and both are excellent quality. Both have top-fill and juice-flow control, are super simple to build, and give outstanding flavour.
As for the differences:
Size: Mini V3 is 19mm wide, V5 is 22mm. Both are quite tall, so while the V5 will sit nice and flush on your iStick 30, if height is an issue, the Mini wins. However capacity-wise, the V3 is 2ml, the V5 is 4.5ml I think. V5 also comes with a steel tank section that ups that to 5ml, or as an unbreakable option.
Airflow: The Mini V3 is a pain to adjust. It requires taking the tank off your mod, unscrewing the 510 pin, and poking a small flathead inside the tank, while you draw on it to find your sweet spot. In contrast, the V5 is much simpler, there is a ring on the bottom that lifts up to reveal an octagonal piece inside, with dots on each side, from 1 to 4 (mirrored on the opposite side). You turn the ring to the dots you want, and slide it back down.
However, the V5 on the tightest setting is a fairly loose draw. The Mini V3 can be adjusted much tighter than the V5. Plus, it's a continuous adjustment, rather than the four "steps" of the V5. I'd say 2-dots on the V5 is equivalent to fully open on the V3, and 1-dot on the V5 is 1.5x as open as the Nautilus Mini on it's max airflow (though I can't remember, it's been nearly a year since I had one of those).
As another option, there is an airflow reduction kit for the V5, but as far as I'm aware, the only one available is the official one, which comes in at £9 extra for a few tiny pieces. It's an option though, don't rule out the V5 just because of the airflow, I love the M2L draw of it.
Build deck: Much improved on the V5. The V3 is simple, you have two screws, you trap the leads under the screws, bob's your uncle. However it can be fiddly getting those leads to catch. The V5 improves on it by having some "guides", so the wire will sit underneath the head of the screw, between the guides and threads. A simple addition, but it's so much easier to build. As far as wicking, both are super simple, you just thread cotton through, and tuck it into the channel, making sure the cotton is short enough to not be bunched up at the bottom.
Flavour: On-par, or at least I haven't noticed any difference. Both are excellent for flavour though. I enjoy my sub-ohm, juicy vapes too, but for low-power, good flavour, these two tanks are my favourites. Of all my devices, my K5 gets the most use. I also really like the ability to swap to 4-dots for a good long lung-inhale to get my morning niccy hit
As far as leaks go, I have had minor seeping from the airflow on both, but it's always been when I've first got them, and trying to find the sweet spot for cotton/juice flow control. You'll have that with any RTA until you figure it out. Now I've got them dialled in (V3, 2mm coil, 1.5-2 full turns for juice flow, V5, 2.5mm coil, 1 full turn of juice flow, both with 50/50 juices), I don't get any leaking whatsoever.