This post is for four dongles: Shanling UA5 Cayin RU6 iFI GO Bar iFI GOld Bar I only used the Moondrop Kato DD IEM for impressions from an iPhone 13. I didn't use any other IEM or any other sources. 3.5mm output only. I used the Cayin USBC to Lightning Cable that came with my personal RU6 except for the GOld Bar, which I had to use its included USBC to Lightning Cable since the Cayin cable won't work with it. Shanling UA5: Out of the four dongles, the UA5 is my least favorite sounding wise, but my favorite on I/O and smart features. I really like the knob for volume control and to control different settings on the UA5. It is smart to have a battery setting (since UA5 has a built in battery) where you can have the UA5 run only via its battery (and not taking power from your iPhone. If you had other Shanling devices you can control DAC output to Single/Dual, Gain, SPDIF out and screen settings. For the sound, it sounds like my other Shanling devices I have in my bedroom (UP4 Bluetooth Amp and M3X DAC), it's neutral with minor signs of warmth. Lows are Highs are sufficient but not class leading, but the mids are solid with minor hints of brightness. Music itself has liveness but when comparing to other devices it ain't special. With that being said, it isn't a POS device and I think for most people they will be fine with the sound. It just doesn't have any "special sauce" to take it to the next level, even if I was listening to it for hours with no real major complaints. Average is most likely the word I would use as a sound summary. Still worth it if you get it for a good price but I would be careful if using neutral/bright/AZN vocal fetish BA IEMs since it might be too bright. Bright DD IEMs it might be ok but I wouldn't count on it. Cayin RU6: I didn't use the loaner RU6 since I got my own RU6 unit, and thus I used my own RU6 for this. I got the RU6 for its killer OG R2R sound for a good price, and I haven't been disappointed with it since. On the IO the button clicking does get a little annoying on the volume control but then again it is a R2R dongle, so it is needed for step-by-step volume control. See this post from mine for more details on the RU6 sound. Still love it after trying the loaners. iFi Go Bar + GOld Bar: Both Dongles will be similar in IO and sound signature, but differences if you read below. Lets get the IO out of the way, it's fully button based with no OLED/LED screen. To see what is turn on/off, the bottom of the unit uses LED lights to tell you bitrate and options on/off. I'm not a fan of this at all, but since both units don't use a screen then in theory the units will last longer since on the other units you need the screen to see what options you are adjusting. So if the screen dies out, you are semi-screwed. On the side of the unit it has buttons plus iFiMatch switch. Another button is to turn on xSpace and xBass DSP stuff, which I didn't use at all. Hold both volume buttons and you can turn on/off Turbo Mode. Turbo Mode makes a good difference on sound quality and it made the DD drivers in my Kato preform better. With that being said, it might be best to not use Turbo Mode on really sensitive IEMs. So the differences: Build Quality on Go Bar is standard dongle hard plastic thingy (dunno the build quality) that is better for outdoor use (but still use the included case), while the GOld Bar is in its stupid gold that get marks on it super easy is terrible to look at it. It isn't an OAFAS product, but it looks like one. Really hate the look of the GOld Bar and I would personally never get it since it looks dumb. Sound differences: Both have a similar sound signature: Warm-Neutralish that at least goes up a few levels above the UA5 to me, more highs info than the RU6 and more defined lows also than the RU6. The mids to me on both dongles aren't tasty to me like the RU6 (since I prefer how the OG R2R sound handles mids), but they won't lie to you and is very defined with vocals and not sounding too upfront. GOld Bar however is the better unit than the regular Go Bar, it is at least two levels up IMO than the Go Bar and I see why people really like to get their hands on the GOld Bar. I think the GOld Bar is for the serious music listener who want the best a dongle can perform without lying to you if the recording is good or bad. The RU6 on the other hand has the OG R2R sound that messes together, and I prefer that if I had to be honest. Oh yes, RU6 has more sound staging over the Bar units but not a lot more. Final Thoughts: None of the units sounds like shit. UA5 while being the weakest of the bunch is still a solid listen. End of the day it will come down to what type of music you are going to listen to from your source. I listen to non-audiophile type recordings on my iPhone 13 for casual listening, so the OG R2R sound of the RU6 is the better choice for me (since I am very bias). If you demand something that is more honest and can almost punch with desk setups, GOld Bar can be a good choice if you are do enough serious listening from your phone devices.