There are a lot of claims by manufacturers of having the "killer" this and "killer" that ...
One of the most targeted products is the Kayfun. Without doubt, the Kayfun is one of the best atomizers around. The vacuum based system decimated the Genesis style tanks for ease of use and ease of rebuilding coils ... if nothing else, it beat the Genesis tanks just in being able to lay them down sideways without leaking eLiquid all over the place.
Alas, the Kayfun has its issues too. If you don't wick them properly, they leak and gurgle. The only solution to that is to drain the eLiquid and start over with your coil and wick build. Most of the Kayfuns available have polycarbonate tanks ... polycarbonate is known to leech BPA into liquids even at room temperature (I wouldn't trust a single one with heated eLiquid at all). Even Kayfuns with PMMA plastic, like Polycarbonate, crack and etch with certain eLiquids. Replacing the plastic tank with the optional stainless steel portion available with most Kayfuns is not an ideal solution: you lose the benefit of seeing the amount of remaining eLiquids.
We've recently tested three atomizers that surpass the Kayfun. We can tell you each one and its respective feature set, but we can't pinpoint one as the overall winner. All three have their individual winning feature sets ... overall it depends on how you view these features as important to you that is most important in the decision process. So, here's the three atomizers and why they are better than the Kayfun.
Before we start, we need to discuss the use of the term "pyrex glass" ... none of the products that claim their glass components are "pyrex glass" are right. Pyrex is a brand name, not a type of glass.
There are a number of manufacturers that clone the Squape. Ehpro does it right. Ehpro ship their version with a glass tank. There are a number of features on the Squape that make it a Kayfun killer. The second is absolute ease of use. Even someone new to rebuildables can build a coil without problems on a Squape. The coil base and air flow chimney are both coated with a non-conductive material. That means that even if you have your coil "legs" touching the base or the chimney, you can't short it out. The third is simplicity in filling this and working on it. The base unscrews while the atomizer is upside down. You can then either fill the tank with eLiquid or even work on the coil and/or wicking ... all without having to drain any eLiquid. Working on the coil and wicking is so simple. There is a straight channel for eLiquid flow ... all you do is lay your coil in the center, and wick into the channel. So, let's recap: 1) glass tank; 2) non-conductive coating; 3) easy base removal for filling eLiquid; and, 4) easy base removal to work on the coil/wick without draining the eLIquid. The flavor from your eLiquid is excellent and throat hit is great. Both are easily equivalent or surpass the Kayfuns. The only downside I can think of is that the air flow cannot be controlled, it is fixed and through the 510 connector. Air flow is good though and I have not had a need to adjust it.
Youde UD Aga T7
The Youde UD Aga T7 is also a vacuum system with a glass tank. The feature set is different than the Squape, however. The coil base is somewhat similar to the Kayfun, except that it features four power posts providing the user the ability to have a two coil setup. It is fairly easy to build coils, at least as easy as a Kayfun. The only "glitch" is the lower coil connecting to the lower posts if you build the coils as outlined in the user instructions. You can also simplify the coils with vertical setups and use one tall and one short post. Once you have it build, you make a "fence" of wicking material to prevent leaking and gurgling and re-assemble. Filling with eLiquid is simple. There is a set screw at the top of the tank ... you remove the drip tip, remove the set screw and fill with eLiquid. The level of eLiquid visible in the tank is what you end up with. Replace the set screw and drip tip and vape away. So, let's recap: 1) glass tank; 2) dual coil (or single coil, it's up to you) capability; 3) simple builds with horizontal or vertical coils; 4) very simple filling eLiquid from the top; and, 5) eLiquid levels that you can see. Flavor is exceptional and throat hit is excellent – both are equivalent or surpass the Kayfun. The only downside I can think of for the Youde Aga T7 is the set screw to fill the eLiquid is a hex key type. That's a specialized tool you have to bring along.
Smok RSBT (Rebuildable Stainless Bottom-coil Tank)
The Smok RSBT is a new product from Smoktech. They call it a "hybrid", but it is essentially a vacuum based system that features a glass tank and all silicone seals. We're not quite sure what makes it a hybrid, but it is unusual in having both a glass tank that is visible and an outer shroud to protect the glass tank. Building the coil is simplicity as well and quite similar to a Kayfun build with two power posts. The area where the coil sits is quite large – with a larger air flow chimney and chamber to match. Similar to the UD Aga T7, filling this tank with eLiquid is from the top. You remove the stainless steel shroud (no need to remove the drip tip) ... and use a small Philips head screwdriver to take out the set screw. Fill the tank (it's the same as the Aga T7 in this respect, you need a small needle nose bottle) and put the screw back in. The level of eLiquid visible in the tank is exactly what you get. The Smok RSBT also has a glass drip tip that adds a nice touch to the overall look. The Smok RSBT also features an air flow control ring that is buttery smooth, yet is firm and remains in place once set to what you want. Air flow can be tight or wide open, you choose. Flavor from vaping is exceptional and so is throat hit. Both easily are eqivalent or surpass the Kayfun. The only downside I can think of for the Smok RSBT is that the power posts are tightened by finger, there is no slot for a screw driver..
It's a tough call ... I use all three on a regular basis. I like the Squape because it is a no muss no fuss system. It's the easiest to work with by a considerable margin and perfect for anyone whether new to rebuildables or an advanced user. I like the UD Aga T7 because the flavor is great – similar to the Squape – but it has air flow control. It's also a great atomizer for tons of vape clouds with its ability to have a two coil setup. The first coil I build for it was 0.4 ohms and one terrific vape with tons of vapor. I also wanted to use the UD Aga T7 with regulated devices, so the coil builds are now in the 1.5 ohm range. The Smok RSBT was recommended by a fellow vaper through Facebook. They are not available in Canada yet, so I ordered one from eBay. Excellent recommendation too ... the Smok RSBT is so flavorful and incredibly easy to fill from the top. I did end up flooding the coil chamber though. That was a plus, I found out how simple it is to clear that up with the Smok RSBT – all I did was blow air through the drip tip twice and it was cleared up. With the Kayfun I would have had to drain the eLiquid and take it all apart so that I could also clean the hidden chamber under the coil base.
It is still impossible to pick one of these three as an overall winner. The only advice I can give is to get all three and decide for yourself. It's a worthwhile investment in three atomizers that are outstanding.