If anyone is looking for a seriously stout, dependable, and practically unbreakable work tank… again, I will throw the SJMY Kayfun V5 (Steel Tank option) into the ring. I’ve been using one for 4 or 5 months now… simply put… the easiest day to day work tank I have ever owned. 
I don’t own a KF V5 Mini, but I’m sure the steel tank version is just as indestructible as the tall boy. 
Hehehe 
Day 2 of same coil as previous post. Getting the same flavour at 8W now as with 10W on Day1 and consumption is down from 1 ml/hr to 0.5 ml/hr… an exponential relationship between Watts and juice consumption?
And - SOOO easy to build…
I’ve also read quite a few FT comments about the mini surviving multiple drops even with the glass tank…
Hopefully, we’ll have another KF member added to the list soon… 
Kayfun Prime!
…basically, a baby KF V5, but with a reduced airflow; more like the original KF or Mini V3. Six air flow settings graduating from 1mm to 2mm.
Sadly, I’m not overjoyed with the KF Prime. The machining on both models I’ve received is flawless (SXK & YFTK). However, I’m a little disappointed the ID of the air intake hole, underneath the coil, is NOT 2mm. It’s somewhere between 1.5 and 1.75 mm. 
Seems to me if you’re going to offer a 2mm air intake hole, all parts of the airflow system should be 2mm in size as well. Oh well… first world problems… moving on now.
Still, in all, the KF Prime will prove to be a nice MTL RTA for those in the market.
And for those who are interested… the clones I purchased did have the latest KF logo on the chimney and novelty etching of Russian whereabouts on the steel tank.
Exactly what is the specific problem that this causes in your use of the atty? I have 3 of the SXK versions and am happy with them for my use which is MTL NET. They do exhibit some issues with temp stability in TC mode, so I use them in wattage mode.
Currently my preferred atty for MTL NET is the 22mm Siren V2. They are rock solid in TC mode, and an easy build deck which will take a 3.5mm coil, also a fast dry burn and rewick for NET use. I recommend them highly. Also I give them a slight edge in delivery of excellent flavor profile vrs the PRIMEs.
I sit right between being a MTL/DL hit type vaper… I use a KF 5 and Mini V3 most of the time… it seems to me the KF Prime has even less airflow than the KF Mini V3. So, that’s the issue for me… too little airflow. However, for true MTL type folks, it will vape like a dream! 
If anything, my wife and daughter will love this RTA and it will cause me to slow down and savor my NET vapes a bit more. 
The sxk prime is pretty good. It’s my first Mtl with a replacable coil. A 26650 lasts two days at 11 watts for me. I have been having problems though lately with the bottom section not wanting to open. I can’t decide between that and my berserker. Berserker tastes better but takes a leak 1/3 full, the prime doesn’t and seems less of a hassle.
Try to put the juice in the Berseker under the deck! :piscadela:
I tried both. It’s the vacuum. It goes away after I tip it over, open and close the bottom and reopen the airflow. Juice use has gone way down since the switch to both tanks.
and open the airflow with the berseker facing down, have you tried this?
Hmm, I think I opened the airflow right side up. I’ll have to try it the other way later. Thanks!
Post edit:
I misspoke the other day… I said the KF Prime chimney flue was not 2mm. That was incorrect. I have corrected my wording in the original post.
Do you mean adjusting the airflow?
No, but It’s been fixed. It was the portion that you need to open to change cotton. What was happening was I’d try to unscrew it and the extension adaptor would stick. It disappeared by changing to the standard size.
If that makes sense 
Glad it’s fixed 
Can’t for the life of me work out how the extension adaptor would ‘stick’ Although if you’re (not ''your" !! [this is not aimed at you Buhhh but at everyone who does not know the difference… Sorry it’s a pedant-thing ) happy with a 2ml tank then it’s all good. But if you’d prefer a 4ml tank, can you describe it in other words so we can fix it?
I don’t have the problem with my 2/4ml clone as I kinda’ crank the extension onto the top of the chamber, then crank the top collar onto the glass and bottom collar, so that the complete tank assembly is much tighter than what is needed to unscrew the tank from the build deck and/or adjust the juice flow control. If that makes sense
Maybe you just need to crank the extension on tighter?