Bought it a month ago and replaced a 2i4 1st gen that I had. I wanted the 4 balanced outputs with TRS ports for reamping and went for this one.
In terms of sound, okay... in terms of latency, okay... BUT... it gave me a significant problem. When I turned up the gain above the halfway mark and played loudly, the interface would restart! It couldn't handle the gain. I'm not even talking about turning it up to "three-quarters" or maximum, I couldn't even play. After doing some research online, I saw that I wasn't the only one. The problem has been reported by many users and it surprises me that the company hasn't done anything about it. If you play with low gain, it's okay... but when you buy a car or a motorcycle, the other person can't tell you not to press the gas pedal all the way because it will shut off on you!!!
The problem has been identified in the power supply from the USB. The interface is at the limits of the USB power supply (900mA) and when you ask it for "power" and it needs to draw power from the port (which can't provide more), it crashes.
Right now, it's at the service center for inspection and possible replacement.
I probably won't risk opening the new one. I will return it and choose a different model from the company with a separate power supply.
I speculate that the next generation 4i4 will come with its own power supply precisely for this reason.
A second problem it gave me (which may also be due to the power) is that after heavy use for a long time with recordings, at some point it started producing interference in the monitor speakers. It didn't affect the recording, of course, which was happening normally, but it was annoying to hear it in the speakers. The interface needed a restart to fix it.
In conclusion, if ALL of them are like this and it's not just happening to a few, you should be suspicious. If you want to play with high gain, don't risk it. With low gain, it's simply flawless, with perfect sound like all Focusrite interfaces. I want to believe that it's a hardware flaw in some units (since there are many confirmed cases even abroad) because the company is very good and reliable in the audio industry.

I was the owner of the Focusrite 2i4 1st Gen sound card for five years. I used it for recording guitar, bass, MIDI drums, and it did a great job. That's why I decided to upgrade to the new 4i4. The first change I noticed was in the sound. When I listened to music on the 4i4, the sound quality was superior. The gain and volume knobs were more stable and had a better grip, so my fingers didn't slip. The most important change is the latency. With the 2i4, I recorded with 6ms latency, but now with the 4i4, it's only 3ms. With a project full of VSTs and effects, you can even go as low as 2ms if you record more minimally. But even at 3ms, you don't feel any delay in the sound. The third-generation Scarlet interfaces have the AIR mode, which is a preamp that makes vocals and acoustic guitars sound brighter and more alive. It also has a loopback feature that allows you to record audio directly from the internet to your DAW or transmit audio if you're doing a podcast or radio. Lastly, as the name suggests, this particular interface has 4 inputs and 4 outputs. You can connect a guitar, bass, microphone to the first two, and an amplifier or synthesizer to the other two. I've even made videos on YouTube showcasing the setup, etc. So, go ahead and get the Scarlett 4Life without any worries