Long story short, my Galaxy S8 was not cutting it and I needed an upgrade in the audio department. All I have to say is thay Amazon has one hell of a return policy...I'm not an expert and only have KSC75/SR60/AKG branded Galaxy buds to listen through, but here are my quick thoughts on the following: SMSL Idea: Nice packaging and accessories. Works with the included S8 USB adapter, but has issues with clicking as reported. Sometimes it works, sometimes it doesn't; I don't want to mess with the tricks or firmware downgrade, plus it runs hot, so this one is going back. Sound quality is nice and has a bit of depth to it, though I'm not a fan of what I would call "thick mids". It has very thick and airy mids. Others may love this if you're into vocals, but something doesn't quite click with me overall. The onboard volume buttons are a bit annoying in that you have no clue what the setting is and that it always resets back to the starting point when you disconnect the device. In a way, this one might actually be the best sounding of them all, but it is going back. Hifimediy Sabre 9018: Minimal everything and kind of ugly...but God does this thing ever sound energetic and forward in a wonderful way. It sounds absolutely huge with great depth and a very 3d quality to it. It's ridiculously engaging and fun to listen to, it will quite literally make you want to get up and dance. But unfortunately, it doesnt always play nicely with distorted guitars and makes things sound strange and too harsh in the upper end for rock...Billy Corgan's fuzz tones are hard to bare for example. But if you'e into r&b, hip hop, edm, indie, pop, etc...this thing is just incredible like you wouldn't even believe. Only issue is that it relies on phone volume controls and isn't exactly precise...I want to keep this thing just because of how ridiculous it sounds. Plug and play with S8 adapter, and the site sells a usb c version. A winner for what it does. Fiio Q1: Here's the clear keeper. It's not the best at anything, but it works well for everything that I throw at it. Between the features, analog volume control which is a must for phone use, packaging and accessories, etc...it's the winner. Just a fantastic, cheap, little device. Plug and play with the S8 USB adapter. Definitely shows the merits of having a good all around sound in addition to analog volume adjustment to get things right where they need to be. Hard to believe this thing is only $50. Fiio K1: Great for what it is, nice packaging and contents, etc. Sounds like the Q1 but "more dry" and just a bit more congested. Great budget solution for an overall improvement on stock phone sound. But just like the Hifimediy, the volume adjustment relies on your cell phone or device and may be a bit imprecise when dialing in volume settings. Sending it back in favor of the Q1. Fiio A3: Just like the Q1, great packaging and inclusion of accessories. It has a much better sounding bass boost and is a bit more powerful. Since it doesn't include its own dac and is just an amp, it is working off of my Snapdragon S8's dac. It sounds more congested and way less clear than the Q1, but it also seems warmer and a bit more punchy. This would be a nice budget solution for somebody who isn't after a dac upgrade as well. Also sending it back due to the Q1. So in conclusion...Fiio makes one heck of a bargain with their products; I'm officially a fan and supporter now. I'm keeping the Q1, but the K1 and A3 are equally as well built and just great products. The thing about Fiio's stuff is that it won't "wow" you in any one area, but it works for anything you would throw at it without issue and makes all genres of music sound "good". In short, the Q1 and company turned out to be the most usable. The SMSL has potential but is faulty, and the Hifimediy Is just bonkers...so much fun, I mean just crazy, but it just doesn't work for heavily distorted guitars and can be a bit too harsh for certain things. But still, just amazing at what it does and probably enough for me to keep it; another company that knows what It's doing. Feel free to drop some questions if you want me to answer for you.