I'm quite new to vaping, saw this device in an online store and thought "well this looks interesting, let's order one". I had only 2 days with it (for reasons I'll get into).

What is it?

It's a trigger operated refillable pod system that uses a combination of heat (180°C) and ultrasonic vibration to produce fine vapor/mist (manufacturer claims it's finer than traditional vapes). It does not have a coil, instead the ultrasonic element performs double duty as it heats up during operation and so provides both the source of heat and vibration.

What I like

It's a pod system, which I find nice to swap tanks for different flavors. The pod is easy top-filling. When it works properly (which it doesn't do often) it makes a lot of vapor that is cool and never dry or burnt. It doesn't sputter, spitback, pop or sizzle. The flavorings are preserved and the taste is intensive and unaltered. For some reason it seems to produce more "buzz" for the same strength of nicotine than traditional vapes (maybe it's the finer mist particle size, maybe 320° C of traditional vapes still renders some nicotine into its constituents, maybe it just makes more vapor, I don't know).

Overall I really liked the experience when it works properly (as rare as that is). I think the concept has promise, unfortunately, a concept is all it is at this point because...

What I don't like

Spitback: The manufacturer claims it doesn't do spitback. This is only true once it gets going properly. It happens (especially after refilling, but also when it's not been used for several hours) that it gets swamped and starts to spitback, a lot. There's no easy way to clear it. You can't shake the liquid out. You can't "power draw" trough it as you'd essentially end up drinking a lot of vape juice. About the only way that seems to somewhat work is to put several layers of paper towel in front of the mouthpiece, give it a good draw, change the paper towel, and repeat until it clears. Doing so will easily empty half of the 2ml tank and drain most of the battery, and the whole device (battery, tank and all) will heat up until it's hot to the touch (probably some kind of electronics issue, this will become a running theme).

Non adjustable draw resistance: The pod provides one draw resistance (which is none). It can't be adjusted in any way.

Inconsistent vapor production: When it properly produces vapor, it makes a satisfying lot of it. However most of the time it "shuts off" after like half a second and makes no more vapor until you release and press the firing button again. It's definitely not that the liquid wouldn't get to the atomizer or anything, because you can keep re-pressing the firing button and get more vapor. It's clearly some kind of electronic issue.

Long ramp up time: The device takes 2-3 seconds before it starts producing vapor after the firing button is pressed. You can get used to it, but it's just awkward. I don't know why this is the case, but I suspect it's got to do with the technology itself (the ultrasonic element probably just doesn't get up to temperature very fast). Seems like a design issue to me tough, because you could easily include a "preheater coil" that warms the liquid up to working temperature for the ultrasonic element to do the rest.

2ml tank is kinda small: It seems to go trough a lot of liquid fast, so the 2ml tank is kinda small.

Battery life: Battery doesn't last very long. You can't take this thing away from the vicinity of a source of power because it'll run flat in a couple hours leaving you stranded. This is probably a combination of design issues (small battery of 1500mAh combined with technology that seems to require a lot of energy).

Deceptive Weight: The device plus pod weighs 180g (150g for the battery and 30g for the tank). It feels substantial, you'll think it's got a lot inside. However, upon disassembly I've discovered that the innards are only 46g, the case alone is 70g and the firing button is 21g. If it wasn't for the issues with battery life, I could let that one slide, but really, I'd much rather prefer a 3x larger battery and a lighter housing than what they've done here. picture album.

Weird firing button: The firing button mechanism alone takes up about 12% of the weight of the device, and it sticks out a fair bit so it's liable to get snag on clothing and whatnot, and for all these drawbacks, it's not really any better than traditional firing buttons, just different, unnecessarily so.

No draw activation: For the fact that it's practically an AIO device, and not a cheap one at that, you'd expect it to come with draw activation, but no, doesn't have it (and hence also no way to throttle power depending on draw strength).

Unusable status display: The device uses a combination of blinking and 5 LEDs to indicate errors and charging status. For the love of... just stick a tiny OLED display on it! It's not too much to ask for a $70 device to have a usable status display that'll cost you like $0.5 to source in china (seeing as it's made in Shenzhen anyway...).

Tank holding: The tank is held in the device by 2 small magnets and it's easy to dislodge.

Tank refill unlock: In order to "open" the tank you've got to twist the mouthpiece 90° which opens two small ports. There's no "click" or anything to indicate a secure end position, it's just the limits of turning. It's not that you'd accidentally open the tank, but it would feel better if it "clicked" into the endstops properly.

QA issues: The first device I got crapped out after 2 days. It would turn on and off but pressing the firing button it just blinked 8x indicating "over vaping" (whatever that means). I contacted the company, they asked me for a video, I sent it, they said it's a "short cuircit" and sent me a new one. I received the new device, but that one was broken out of the box and just wouldn't charge. It would turn on when plugged in, but pressing the firing button it blinks 5x indicating "no charge" and no matter how long it was plugged in, it just wouldn't charge. I emailed the company again, they asked for a video again, I sent it, they then informed me it has to be plugged in for a while (a-hahaha), and I told them (again) it wouldn't charge. Finally they informed me they'll arrange for a courier to pick it up in half a month. I offered to send it by parcel service, but they declined citing "but the customs cannot be arranged to declare during this period as CNY holiday", whatever that means. From what I can tell they seem to have a lot of electronic issues, and they don't seem to put their devices trough much (if any) QA process.

What needs to be done

I've got a few suggestions here what they really need to do.

• Have a proper QA process so you don't ship crapping out or outright broken devices to customers, repeatedly in series.
• Put in a larger battery, like 3000mAh or better yet 4500mAh.
• Optimize energy efficiency of the technology
• Fix the swamping/spitback issues and make it possible to easily clear the issue when it happens
• Include a "preheater coil" or other measure to reduce ramp up time.
• Add a thermocouple or two for precise temperature control
• Add a draw sensor so you can modulate the ideal heating/misting rate
• Add an adjustable draw resistance (and sense the set draw resistance with an encoder or variable resistor)
• Get rid of the weird firing button
• Make a lightweight case
• Add an OLED status display
• Add a proper "click" in position for the tank open/close
• Make the battery exchangable
• Add a mechanical, spring loaded retention detent for the tank

Though I fear, the Usonicig Rythm is about the best China can do at this point. It probably needs a company committed to making this work properly, and I'd be very interested in whomever makes one that fixes all the issues. I think there's a lot of promise in such a device because (when working properly) it fixes some of the issues of traditional vaping devices. Even Juuls (designed to be the most friendly vape for those entirely disinterested in the technology) suffer spitbacks, dry draws and burnt flavor.